July 21st, 2021

Changing Primer Type CAN Alter Pressure and Velocity

Primer Wolf CCI Federal Muzzle velocity FPS reloading

We are often asked “Can I get more velocity by switching primer types?” The answer is “maybe”. The important thing to know is that changing primer types can alter your load’s performance in many ways — velocity average, velocity variance (ES/SD), accuracy, and pressure. Because there are so many variables involved you can’t really predict whether one primer type is going to be better or worse than another. This will depend on your cartridge, your powder, your barrel, and even the mechanics of your firing pin system.

BE SAFE: Be cautious when changing primer types. Glen Zediker recommended decreasing your load ONE FULL GRAIN when changing to a different primer type, one that you haven’t used before.

Interestingly, however, a shooter on another forum did a test with his .308 Win semi-auto. Using Hodgdon Varget powder and Sierra 155gr Palma MatchKing (item 2156) bullets, he found that Wolf Large Rifle primers gave slightly higher velocities than did CCI-BR2s. Interestingly, the amount of extra speed (provided by the Wolfs) increased as charge weight went up, though the middle value had the largest speed variance. The shooter observed: “The Wolf primers seemed to be obviously hotter and they had about the same or possibly better ES average.” See table:

Varget .308 load 45.5 grains 46.0 grains 46.5 grains
CCI BR2 Primers 2751 fps 2761 fps 2783 fps
Wolf LR Primers 2757 fps 2780 fps 2798 fps
Speed Delta 6 fps 19 fps 15 fps

You can’t extrapolate too much from the table above. This describes just one gun, one powder, and one bullet. Your Mileage May Vary (YMMV) as they say. However, this illustration does show that by substituting one component you may see significant changes. Provided it can be repeated in multiple chrono runs, an increase of 19 fps (with the 46.0 grain powder load) is meaningful. An extra 20 fps or so may yield a more optimal accuracy node or “sweet spot” that produces better groups. (Though faster is certainly NOT always better for accuracy — you have to test to find out.)

WARNING: When switching primers, you should exercise caution. More speed may be attractive, but you have to consider that the “speedier” primer choice may also produce more pressure. Therefore, you must carefully monitor pressure signs whenever changing ANY component in a load. Glen Zediker recommends decreasing your load ONE FULL GRAIN when changing to a different primer type, one that you haven’t used before.

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July 18th, 2021

Sunday GunDay: Sako TRG-22 & TRG-42 Hunting Rifles in Norway

Many years ago, when we decided to do a story about SAKO’s TRG series of rifles, we remembered our friend Terje Fjørtoft in Norway. Terje has owned, and hunted with, both the TRG-22 (in .308 Win), and its big brother, the TRG-42 (chambered in .338 Lapua Magnum). Unlike many TRG owners in the USA, Terje has carried his “tactical hunters” into the field, and tested their effectiveness on large game in both coastal and mountain environments, in warm weather and cold. Terje tells us the TRGs have proven to be rugged and reliable. And they are accurate. The .308 Win TRG-22 delivers about 0.45 MOA groups at 420 yards shot from bipod. The .338 LM TRG-42 shoots about 0.55 – 0.7 MOA at that distance.

A Tale of Two TRGs by Terje Fjørtoft

I live in Brattvåg, along the coast of Norway, but I hunt and shoot at the nearby island “Fjørtoft” (same as my last name) and a small island outside Fjørtoft. I grew up on Fjørtoft as a child, and we hunt seals there in the spring and fall. The large, top photo shows me with my black TRG-42 338 Lapua Mag (“LM”) during a seal hunt a couple years ago. Click on the thumbnail at right to watch a video that shows me shooting the .338 LM. Most of the photos in this story are from that hunt. Because the .338 LM was really “overkill” on the seals (and expensive to reload), I replaced that rifle with a TRG-22 in .308 Winchester.

We hunt seals primarily for wildlife control. This is because the seals carry an internal parasite, called “Kveis”, a small worm that breeds inside the seals (after eating contaminated fish). When the seals expel the Kveis into the water, the Kveis larvae are consumed by the fish and then the fish become unfit to eat. The parasite literally eats the fish from the inside out. It’s not very pretty and it has hurt our Norwegian fishing industry. So there is an important purpose for our seal hunting. We hunt mostly from islands, targeting the seals in the water, and retrieving them with a small boat.

Because the seals spend most of their time in the water, a seal-hunter needs a very accurate rifle [to take head shots at distance]. I like the TRG-22 because it is very accurate out of the box, with a very nice bipod that works well in the field. The stock is comfortable with good adjustment range. The TRG features a 10-rd magazine and the barrel is pre-threaded for a muzzle brake or suppressor.

I have also used my TRGs for hunting big game, deer and what Americans call “Elk”. You can see, further down on this page, a picture from a hunting stand taken late in the evening, in the fading light. Yes I successfully bagged a nice buck during that trip with my TRG-42. When hunting, I use a Leica 900 rangefinder, Swarovski 7×42 Habicht binoculars, and a Silva windwatch. For Optics on the TRG-22, I have a Zeiss 6-24×56 scope, in Tikka Optilock rings. To get more scope adjustment I milled 0.9 mm off the front scope base mount. The Zeiss is great for viewing small targets past 400 meters. It was very difficult to find a longer shooting place than 575 meters on this Island (Uksnøy) but I found a place where I can shoot out to 930 meters, and I’ve made an 80-cm steel gong for a target. At this range, the bullet must fly nearly all the distance over the water.


Terje Shooting the TRG-42 without suppressor. Big recoil, big flash.

Both the TRG-22 and TRG-42 are very accurate right out of the box. The only thing I did before I first shot the TRGs was to clean the barrels very thoroughly. This is because the SAKO factory test shoots the gun without cleaning the barrel. I also adjust the cheek piece upward when shooting the rifles with a big scope. However, if you raise the cheek piece too high you can’t get the bolt out without removing the whole cheek piece. The only real modification I’ve made to my TRGs was to put rubber foot pads on the feet of the SAKO factory bipod. This gives the bipod better grip on slick surfaces such as concrete, or the rocks on the offshore islands.

.338 LM vs. .308 Win — Smaller Can Be Better
A few years ago I had a black TRG-42 (338 LM), but after a year, I sold it, and ordered a TRG-22 from the SAKO factory. After a one-year wait, I got the new green TRG-22 in February this year. One main reason I changed to .308 Win was the cost of ammo. I can reload .308 Win ammo for about one-third the price that it costs to reload .338 LM. One other reason is that my usual shooting distance is about 390 meters–at that distance the .308 is more than effective enough. Also, with the .338 LM, the barrel and the suppressor heated up after only a few shots, but with my new .308, I can shoot at my own pace without this problem. After my most recent shooting trip I once again confirmed how accurate, and fun-to-shoot, the TRG-22 is. I think now the TRG-22 has become my favorite plinking gun.

Though it is fun to experience the big boom and flash of the .338 LM, I’ll admit that it is just too much rifle for most applications. The .338 LM is REAL overkill for seal hunting. Here in Norway we have a rule that the smallest caliber we can use is 6.5×55 with a 140gr (or heavier) bullet, but everyone who hunts seals knows that the seals stay mostly in the water, and therefore you must take a headshot at distance up to about 200 meters. Making the headshot with a smaller caliber is advised for two reasons. First, when a big .338 bullet hits the water, there is a danger it will skip and ricochet quite some distance. Second, if you use too powerful a load/gun/caliber and take a headshot on a swimming seal, the seal sinks like a rock.

Reloading for the TRG-22 (.308 Win)
With the TRG-22, I found it was easy to get an accurate load. My groups with 155gr Scenars are consistently good with a variety of different powders. I’ve tried both light and heavy bullets, but I favor the 155gr Scenars over the 185gr Scenars because the 155s fly a lot faster and drop less.

Three loads (all with Fed 210m primers) that have worked well are: 155gr Scenar with VV N150, 885m/sec; 155gr Scenar with Norma N-11, 890m/sec, and 185gr Scenar, VV N150, 770m/sec. Norma N-11 is a low-cost powder for target shooting. N-11 is similar to Norma 203B or Norma 202 but it varies quite a bit from lot to lot.

I use a RCBS Rock Chucker press, and currently use a standard RCBS full-length die kit to reload my .308 rounds. However, I recently ordered a Redding Competition 3-die set with a .335 bushing. I look forward to trying the Reddings. I have just started to test different seating depths. The 155s just “kiss” the lands at 74.10 mm. I’ve tried 74.00 mm, 74.10 mm and 73.55 mm, but so far saw no significant differences.

Reloading for the TRG-42 (.338 LM)
For the .338 LM, I started with a 250gr Scenar and 95 grains of Vihtavuori N-170. That load was very accurate at about 850 m/sec, but it produced excessive muzzle flash. And, in the winter, the muzzle velocity was inconsistent, and there was too much unburned powder. Next I tried Norma N-15, which proved very accurate at about 880 m/sec. With that load I shot my best TRG-42 group at 380 meters. I set the 250gr Scenar to touch the rifling with 93.2 mm COAL, and I used Federal 215m primers in Lapua-brand brass. Norma MPR2 and VV N-560 (860 m/sec) also were very accurate with the 250 Scenar.

My seal hunting bullet was the 200gr Nosler BT. This bullet grouped very well with 90-94 grains Norma N-15. Velocity was about 970m/sec if I remember correctly. I also tried the 300gr Sierra MK, and got 1/2″ 3-shot groups at 100 meters with 93.5 grains of VV N-170, but this combination produced terrible groups at longer range.

Loading for the .338 LM was not difficult — about the same as loading for .308 Win, except that you use nearly twice the amount of powder. I didn’t crimp the bullets in the neck, didn’t use any special tricks or neck lube. I used RCBS .338 LM full-length die. That functioned, but it would not be my first choice today. Overall, my better loads in the .338 shot in the 0.5-0.7 MOA range. My best group was four shots in 25mm (1″) at 380 meters (416 yards).

Hunting in Norway


I’m not a competitive sport-shooter. Normally, the only time I go to a “commercial” rifle range is to take the test for my hunting license. Every year, I must re-qualify for a shooting license to hunt big game and seals.

Hunters Tested Annually
In Norway, you must pass an actual shooting test before you can hunt big game. This test requires five shots at a deer silhouette target at 100 meters. No rests are allowed–you must shoot off-hand or with a sling only. You have to place five shots inside a 30 cm circle over the front leg.

Every big game hunter that passes this test is authorized to hunt at “dusk and dawn” and in moonlight. So, we do a lot of our hunting in the twilight hours. However, no night-vision or artificial illumination (spotlights) are allowed. We usually hunt deer at dusk and dawn. In the evening, we go on post two to three hours before it is dark, and sit there waiting for the deer to show up–hopefully before it is too dark. In the morning we go to the post one hour before you see any light of the sun, and wait for the deer to show up until the daylight. But when it is full moon we sometime have enough light to hunt in the middle of the night. In the photo, you can see a deer through the scope of my TRG-42. This was very late in the evening. CLICK HERE for BIG Photo.

Sound Suppressors for Hunting Rifles

Suppressors are legal to use for hunting in Norway. I have suppressors on all my rifles, even my little CZ 452 in 17 HMR. To me, shooting a rifle without a suppressor is like driving a car without an exhaust system. The suppressor reduces both noise AND recoil significantly. With a good suppressor, there is no loss of accuracy. The only “negative” in using a suppressor is extra weight on the end of the barrel.

I crafted my own home-made suppressor. It’s similar to my commercially-made TRG-22 suppressor, but the core is made from titanium to be lighter in weight and more corrosion-resistant. I used a lathe at work to craft the inside of the new suppressor. The core of the unit is built from a 27.5 cm X 40mm round bar of titanium while the outer cylinder is made from a 42mm stainless steel tube. I wanted to use titanium for the exterior cylinder as well, but I couldn’t source the right size titanium tube.


Commercial Suppressor on TRG-42

Comparing .308 Win vs. 6mmBR
I also have a 6BR hunting rifle (compensated of course). I have a lot of field time with the 6BR rifle, and feel very confident with that gun. When I got the Krieger 6mmBR barrel on the SAKO Varminter, I fell in love with that rifle from day one, and that rifle is my first choice for small game hunting.

I also like the TRG-22 gun very much and enjoy it more and more with each new field trip. That .308 is my big game rifle and my long-range target rifle.

I recently tested my TRG-22 rifle at 387 meters. This was just “fun shooting” at steel plates, and I didn’t measure groups. But I was happy with the results. Once I corrected for the 5 m/sec crosswind, I was able to put five successive shots on a 10 cm (4″) diameter steel target at 387 meters (423 yards).

My SAKO Varminter in 6mm BR and my TRG-22 are two very different rifles. The TRG-22 is much heavier. I guess the TRG-22 is about 6.5-7 kg while my SAKO 6BR is about 4.5-5 kg, both with suppressor, scope, and bipod. The 6BR with suppressor is much quieter than the TRG-22 with suppressor. The recoil of the 6BR is a lot softer than the TRG-22. So far my 6BR is more accurate. A typical three-shot group with the 6BR is 25-40 mm at 387 meter (423 yards), and that is with just 10X magnification from a Zeiss scope. With my TRG-22, my 3-shot groups run about 50-60 mm, shooting with bipod and beanbag. But I think with a better .308 Win reloading die and more practice, I can improve my groupings with the TRG-22.

SPEC SHEET

The SAKO TRG-22 and TRG-42 are built in Finland by SAKO, a subsidiary of Beretta. In America, the guns are distributed by Beretta USA. Both TRGs (22/42) are available in forest green or a matte black textured finish. A two-stage match trigger is standard.

The stock is somewhat unconventional. It is an external shell, bolted to an internal metal chassis. The action bolts directly to the chassis, without bedding. The injection-molded stock is adjustable for comb height, length of pull (with spacers), vertical butt-pad height and cast-off.

Weight TRG-22
4.7 kg (black)
4.9 kg (green)

Barrel TRG-22
660 mm (26″), hammer-forged, optional stainless or phosphate finish

Capacity
10-round Mag (TRG-22)
7-round Mag (TRG-42)

Calibers
.308 Win (TRG-22)
300WM, .338 LM (TRG-42)

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July 9th, 2021

Forster Co-Ax Press — Video Shows How It Functions

Forster Co-Ax Coax Reloading Press Grafs Grafs.com Sale Co-Axial rockchucker

Forster Co-Ax reloading press videoIn recent months, Forster Co-Ax® presses have been hard to find, as demand has out-stripped supply. But the folks at Forster Products are working hard to get these excellent presses out to vendors. Be patient, check with multiple sellers, and you should be able to find one.

If you are not yet familiar with the many unique features of the Forster Co-Ax, we recommend you watch the video embedded below. This shows how the press operates and highlights the design elements which set the Co-Ax apart from every other reloading press on the market.

Video Shows Special Features of Forster Co-Ax Reloading Press

Forster Co-Ax Press Video Review
This is a very thorough review of the Forster Co-Ax done by Rex Roach. This 14-minute video shows the key Co-Ax features, explaining how the floating case-holder jaws work (3:30 time-mark), how the dies are held in place (4:40 time-mark), how spent primers are captured (6:10 time-mark), and how to set the primer seating depth (10:00 time-mark). We’ve used a Co-Ax for years and we still learned a few new things by watching this detailed video. If you are considering purchasing a Co-Ax, definitely watch this video start to finish.

Forster Co-Ax Coax Reloading Press Grafs Grafs.com Sale Co-Axial rockchucker

The Co-Ax case-holder features spring-loaded, floating jaws. These jaws have two sets of openings, small and large. This allows the system to adapt to various rim diameters. The jaw plates can simply be reversed to switch from small jaw to large jaw. In the photo above, the Co-Ax is configured with the large jaw openings in the center.

Photos are screen shots from Forster Co-Ax Review by Rex Roach on YouTube.

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July 5th, 2021

Handy Pocket Magnifiers Help with Many Reloading Tasks

Magnifying lens LED light relaoding

pocket fold-out magnifierWhat is the most-used piece of equipment on this Editor’s reloading bench? No it’s not my Rock-Chucker press, my priming tool, or even my calipers. The one item in near-constant use is a small, folding magnifying glass. Mine folds into a square case and offers 4X viewing with an 8X bifocal insert. With this handy tool I can inspect case mouths for burrs, check primer pockets, inspect meplats, and look for flaws on bullet jackets. I also use the magnifier to see rifling marks on bullets seated into the rifling, or check my bolt for galling. The number of uses is nearly endless. I keep one magnifier at my reloading bench and another in my range kit.

Folding magnifiers are so handy yet inexpensive that you should own a couple spares (including one in the range box). I bought my magnifier in a book-store, but you can also find them on Amazon.com and FoldingMagnifier.com starting at under $2.00. To see inside cases and dies and view fine details, consider the 5X Meromore Folding Magnifier with a built-in, battery-powered LED light, plus a 11X high-magnification insert.

With a decent small magnifier, you can easily see any minute flaws in your barrel crowns. That’s important because crown damage can cause hard-to-diagnose accuracy issues. We’ve known guys who spend weeks tinkering with loads, when the real problem was a worn-out or damaged crown.

The slide-out iLumen8, shown at left in top photo, offers 3X power with built-in illumination. An “Amazon’s Choice” item, this palm-sized magnifier is $18.95 on Amazon.

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July 4th, 2021

Will Carbon Build-Up Inside Cases Raise Load Pressure?

Carbon fouling case cartridge interior Pressure volume ultrasonic

As a cartridge case is reloaded multiple times, burnt powder residue and carbon builds up on the inside of the case. Unless the case interior is cleaned in some fashion, eventually you’ll see a slight reduction in case capacity. One of our Forum members from Australia wonders about the effects of reduced case capacity: “If the capacity of the case decreases as the crud builds up, then it effectively reduces the size of the cartridge (inside). Wouldn’t that change the pressure produced from that of an equivalent clean case?”

Interesting Test of Case Capacity Changes
Forum member Fred Bohl has actual test results that can help answer the above question. Fred proved that, over a 20-reload cycle, the case capacity of uncleaned cases did decline a small amount. However, surprisingly, this did not seem to affect the actual chronographed velocity of the load. Extreme Spread (ES) did increase, but Fred believes the higher ES was due to changes in case-neck tension, rather than due to the slight reduction in case capacity. Fred reports:

“Back when beginning to use ultrasonic case cleaning, part of the motivation was to get the inside clean based on the assumption that allowing burnt residue to build up inside cases would affect capacity, and, ultimately, performance. An experiment was done to test this hypothesis. The load used, 30.5 grains of RL15 behind 107gr SMKs in a 6mmBR, was selected for best group and lowest ES in prior load development. It turned out to be 92% of initial case capacity and neither “full” or compressed. (I would suspect that different powders, load weight, and total case capacity might produce very different results.)

We took 30 cases of identical initial capacity and tracked three lots of 10 each:

LOT 1: No Internal cleaning
LOT 2: Cleaned with media in tumbler
LOT 3: Cleaned with Ultrasound machine

Each case (in each lot) was shot and reloaded 20 times. The simplified results after 20 reloads of each lot were as follows:

Lot 1 (not cleaned) – 0.3 to 0.4 gr. loss of capacity, 5 to 8 fps greater ES.
Lot 2 (tumble cleaned) – 0.1 to 0.3 gr. loss of capacity, 4 to 6 fps greater ES.
Lot 3 (ultrasonic cleaned) – no loss of capacity, no detectable change in ES.

FINDINGS
There was no detectable correlation of velocity change to the lots. An oddity was that on very hot days Lot 1 velocities were, occasionally, slightly higher. From results of another ongoing test, I believe the above differences in ES are probably due more to variance in bullet grip tension than case capacity. The ultrasound cleaned cases (LOT 3) did maintain the lowest ES, but we are not 100% sure of the reasons why. More consistent bullet seating might be the reason.”

Carbon fouling case cartridge interior Pressure volume ultrasonic

Editor’s NOTE: Fred’s results do suggest that carbon build-up inside the uncleaned cases might cause a slight increase in pressure that shows up on hot days. Fred has posted that: “A local shooter reported doing the 20 reload, no-clean test on a .308 that gave a loss of capacity of 2.0 grains, doubled ES and significant velocity changes. However, I don’t have any details on his load weight or powder.” Obviously a lot of carbon can build up with 20 reloads. Many shooters retire their brass before then.

Ultrasonic Cleaning and Neck Lube
Some time ago, Jason Baney did a lengthy test on ultrasonic cleaning. Jason found that with his ultrasonically-cleaned cases, the inside of the necks got so “squeaky clean” that he needed to use dry lube in the necks. Jason uses the $10.95 dry lube kit from Neconos.com. This applies ultra-fine Moly powder to the neck using small carbon steel balls.

Neconos.com moly neck lube

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July 1st, 2021

Tips for Using Lee Collet Dies for Neck-Sizing Brass

LEE Precision Collet Die

Editor’s NOTE: We generally recommend full-length sizing your cases. But there may be some situations where you may want to body-size your brass in one operation, and then neck-size the case as a final operation for reduced run-out. Or, perhaps you have a non-bushing FL sizing die and you want to modify the neck sizing. This article explains how to use a Lee Collet Die to size case-necks.

For those who prefer to neck-size their brass (rather than full-length-size), the LEE Collet Die is a popular, inexpensive option. It works by having collet tangs or “fingers” press the neck against a central mandrel. A collet squeezes the case neck against a precision mandrel for a perfect fit with minimum run-out. The benefit is that you get a very straight neck, which is sized consistently from top to bottom. Canadian shooter Jerry Teo explains: “LEE Collet Dies produce sized cases with very low runout (measured runout is under .001″ using a Sinclair concentricity gauge). You also don’t get the build-up of brass at the base of the neck, as can happen with bushing neck dies. The neck-shoulder junction stays nice and crisp.”

Here’s a good video that explains how to use a Lee Collet Die to Neck-Size .243 Win brass:

UPDATE to LEE Collet Dies — Neck Protrusion Change
The Lee Precision website notes a small design change: “If you’re a long-time user of Lee Collet Neck Sizing Die you may notice we have modified the Collet so a small portion of the neck protrudes through the end of the Collet-sizing portion. This often-requested modification was implemented in 2019. This change allows the portion of the neck that protrudes above the Collet to remain in its fire-formed condition. This provides a natural flare to the case neck allowing easy and concentric seating of bullets. This is especially important when seating cast bullets or low-drag coated bullets.”

LEE Precision Collet DieTIP ONE — Adjusting Tension
LEE Collet dies don’t have a specific mechanical adjustment for neck tension. But you CAN easily modify the die to provide more or less tension. If you want to adjust the neck tension using a Lee Collet die, you can simply chuck the mandrel in a drill and reduce the diameter with some sand-paper (to increase neck tension) or you can order a mandrel the next caliber larger and turn it to whatever diameter you want (the larger the mandrel diameter, the less the neck tension). You can also order custom mandrels from Lee sized to any diameter you want.

Regarding neck tension, Boyd Allen makes an important point: “The only way to properly get more neck tension with collet dies is to either reduce the diameter of the mandrel, or order a smaller-diameter mandrel from Lee. I remind folks that adjusting the die position to have more toggle at the top of the ram stroke (not the factory recommended method), or leaning on the press handle with more force than recommended will NOT increase neck tension.”

No Custom Lee Collet Dies For Now
In years past, Lee also offered Custom Collet Dies, made from two fired cases. Hopefully these will be available in the future. However, earlier this year, Lee announced it had suspended sale of most custom dies including Collet Dies: “March 17, 2021: Due to unprecedented order volume, we have suspended custom services for Collet Necksizing Dies, Full-Length Sizing Die Sets, Quick Trim Dies, Case Length Gauges, Factory Crimp Dies, and Bullet Molds until we are able to meet the required volume of our standard products.”

TIP TWO — Polish and Tune for Easy Case Removal
Some users have complained that their Collet Dies grab the case-neck too firmly, making the case hard to remove. There are solutions to this problem. First inspect the collet fingers and smooth the inner surface up a bit with polishing compound or an extra-fine sanding pad. Second, you can open up the fingers a little bit. LEE recommends that if your Collet Die is sticking, take a steel punch and tap the fingers apart a little bit so that the natural “unloaded” position is wider. Lastly, you should lightly lubricate the outside of the collet fingers (see arrows) before you re-assemble the die. This will ensure they slide smoothly. Also, to prevent the collet fingers from closing too tight, never load up the die with your press without putting a case in place first. Without a case neck between the collet fingers and the mandrel, the collet can clamp itself too tight as you raise the ram.

TIP THREE — Always Have a Case Inside When Operating Collet Die
Our friend Boyd Allen tells us that you need to follow directions and NEVER operate the die without a case inside. Boyd explains: “This is because doing so will spring the quadrents of the collet inward so that they interfere with the insertion of a case, and the user will have to figure out how to undo the damage if the die is to operate properly. This advice would not be needed if everyone read the instructions before using the die…. but many times, they don’t. Another thing that I tell new users is to take the die apart so that they will have a better chance of understanding how it works.”

TIP FOUR — Size Twice and Spin Your Case 1/8th Turn
After reaching fully “down” on your press handle, withdraw the case about an inch and manually rotate it about 1/8th (NOT 1/4 or 1/2) turn while still in the shell-holder, then size again. This will place the die’s collet petals on the four “high spots” of the case neck and will result in a rounder, more evenly-sized neck with slightly more bullet tension. This takes only about one second more per case and is well worth the slight extra effort. (We thank reader Stonecreek for this smart tip).

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June 27th, 2021

Sunday GunDay: Tennessee Triple — Voldoc’s Varmint Rifles

Varmint rifles 20 BR Stiller Diamondback 6mm Dasher

Shooting Prairie Dogs at extreme long range takes some highly specialized equipment. Forum Member VolDoc and his friends have taken long-range varminting to a whole new level. With his Savage-based, Hart-barreled 20 BR, VolDoc managed a verified 1,032-yard Prairie Dog kill, possibly the longest recorded with a .20-Caliber rifle. But that’s just part of VolDoc’s impressive precision varminting arsenal. Here we showcase three of VolDoc’s accurate rigs: his stunning English Walnut Diamondback 6BR/Dasher, his Nesika-actioned “Orange Crush” Dasher, and the 1K Prairie Dog-slaying 20 BR Savage.

Diamondback Switch-Barrel Rifle Specifications
The action is a Stiller Diamondback, drop-port. The custom stock is similar to a Shehane ST-1000, but crafted from 40-year-old English Walnut. [Editor’s note: the wood on this gun is gorgeous!] There are three barrels for the gun with three different chamberings: 6BR Brux 1:8″-twist HV; 6BRX Krieger 1:8″-twist HV, and 6mm Dasher Krieger 1:8.5″ twist fluted straight contour (no taper). The scope is a Nightforce 12-42x56mm, with 2DD reticle.

Stiller Diamondback 6mm Dasher English Walnut

Comments: This rifle is a good study in comparison of the three different chamberings. On the same rifle platform (same stock and action), each of these barrels had killed prairie dogs over 1,000 yards. So if someone asks which is best, a 6BR, or 6BRX, or 6 Dasher, VolDoc says they are all effective. The improved cartridges will deliver higher velocities, which can be an advantage. On the other hand it is simpler to load 6mmBR brass right out of the box, and it’s easy to find an accurate load for the 6mmBR (see photo).

Stiller Diamondback 6mm Dasher English Walnut

Nesika 6mmBR/Dasher Rifle Specifications
VolDoc’s “Big Orange Crush” rifle has a stainless Nesika ‘J’ action, with 2 oz. Jewell trigger, in a painted fiberglass Shehane ST-1000 stock. Originally a 6BR, the gun is now chambered as a 6mm Dasher with a .271 no-turn neck. The barrel is a 1:12″-twist Krieger fited with Vais muzzle brake. On top is a NightForce NXS 12-42x56mm scope with double-dot reticle. The double-dot gives precise aiming and lower dot can be used as an aming point, when you need a few more MOA of elevation in the field.

Nesika 6BR 6mm Dasher

Comments: Big Orange Crush shoots 87gr V-Maxs into bugholes at 3,400 fps. VolDoc’s load with the 87s is very stout, more than 32 grains of Vihtavuori N-135 with Wolf SRM primers. Cases are full-length sized, with an 0.266″ bushing for the necks.

Nesicka 6BR 6mm Dasher
This 3400 fps load with the 87gr V-Maxs has accounted for hundreds of Prairie Dogs killed from 97 yards to 1,050 yards. The 87gr V-Max at this speed literally picks Prairie Dogs up and throws them 10 feet vertically and laterally. VolDoc reports: “The barrel now has more than 3,000 rounds down the tube and exhibits little throat fire-cracking and no loss of accuracy. I can’t explain why, it just hasn’t deteriorated yet. This rifle is my best-ever ‘go-to’ Prairie Dog rifle.”

Savage 20 BR Rifle Specifications
The action is a Savage Dual Port, with an aftermarket Sharp Shooter Supply (SSS) 4 oz. Evolution trigger. The stock is a modified Savage factory unit that has been pillar-bedded. The factory barrel was replaced with a 28″ Hart stainless, 1:9″ twist barrel fitted with a Rayhill muzzle brake. The gun is chambered in 20 BR with a 0.235″ no-turn neck. Kevin Rayhill did the smithing. To provide enough elevation to shoot at 1,000 yards plus, Ray fitted a +20 MOA Bench Source scope base. This +20 rail is very well-crafted, and made especially for the Savage Model 12.

Savage 20BR

Comments: VolDoc reports: “When I got the Savage back from Kevin Rayhill, it still had my 6 BR factory barrel on it, as I use it to compete in Factory-class regional matches. I put on the new 20 BR Hart barrel Kevin had chambered and quickly put in a full day of load development using the 55gr Bergers (0.381 G1 BC) and the 40gr V-Maxs. Both proved very easy to tune and I soon had my loads. My 55gr Berger load with runs about 3590 fps. Varget was very accurate with the 55s (see load dev. targets below).

Savage 20BR load development targets

The mild recoil of the 20 BR, along with a very good muzzle break (Rayhill’s design) enables me to spot every hit or miss myself. Kevin also re-contoured the underside of the Savage stock so it tracks straight back on recoil, also making seeing hits easier.”

The 20 Caliber 1000-Yard Prairie Dog Quest

Savage 20BRMaking the 1032-Yard Shot with a 20 BR
by Dr. John S. (aka “VolDoc”)
This article covers my recent successful quest for a 20-caliber varmint kill past 1,000 yards. This may be a first — I couldn’t find anyone else with a confirmed 20-Cal Prairie Dog kill at 1000+. I started a thread on the Varmint section of the AccurateShooter.com Forum about building a 20 BR capable of 1,000-yard Minute of Prairie Dog accuracy and many said 20 Cal bullets just could not do it. Some came to my defense and said those that doubted had never studied the ballistics of the 20BR with the new Berger 55gr bullets now available. Well, folks, I can tell you, hitting a Prairie Dog at 1000 yards isn’t easy — but it IS possible. Here’s how it was done….

Gale-Force Winds and High Temps
After arriving at our Prairie Dog Ranch in Colorado, I soon realized my quest was going to be especially difficult because we had continual 40+ mph winds and 100° heat every day. We had a special place where Birdog and I had made many 1,000-yard+ kills in years past, so I knew the ideal location but needed a small window of opportunity either early morning or late afternoon. Based on past experience, I knew I needed about 21 MOA from my 100-yard zero to get to 1,000 yards. On the first day of the Safari, I shot the 20 BR in the 45 mph brutal winds and heat of 97°. But after about 20 shots, I connected on a dog and lifted him about three feet high. Well, that’s a start.

Savage 20BR

Winds Subside — Here’s Our Chance …
On the second day of our shoot, I had listened to the early weather forecast, so I knew that there was to be a brief period of light winds early in the morning. We were out on the Colorado prairie at daylight and the conditions were perfect. The sunrise was at my back and we had about a 10 mph tailwind. I looked through my Leica Geovid Rangefinder Binos and the Prairie Dogs were out for breakfast. I quickly ranged the targets and found a group at about 1,050 yards. The technique is to find the dogs, range them, click-up according to your ballistic chart and shoot.

Savage 20BR

My first shot was very, very close. I added about four clicks up and a couple of clicks left for windage and let another go. That shot threw dirt all over, but the dog didn’t even flinch. This is another good point to remember about long-range Prairie Dog hunting. To be successful, the dogs can’t be too skittish, because if they have been shot at even a few times, they will go down and stay down. So, you should have an agreement with those in your party as to where each member is going to be shooting and respect this boundary. Drive-by shooting style is OK if that’s your thing, it’s just not mine.

Savage 20BRHitting the Mark — Dead Dog at 1032 Yards
On the fourth shot, I saw the dog go belly up and kick its final throws. My quest for the 20-Caliber 1,000-yard Prairie Dog had become a reality. We confirmed the distance with our lasers at 1,032 yards. Our technique for retrieving a dead dog at that range is worth mentioning. When I killed that dog, I left it in the crosshairs of my Nightforce scope. My shooting buddy kept looking through the scope (of my gun) and guided me to the deceased dog using Motorola walkie-talkies. When I got to the dog I was jubilant. I marked it with my tripod and orange jacket, and we took some pictures. (See view through scope photo below). The 55gr Bergers require a center mass hit as they will not expand, especially at that range. I centered this dog in the head — his BAD LUCK, my GOOD.

After making the 1,032-yard kill, I shot many many other Prairie Dogs with the Savage 20 BR using the 40gr V-Maxs. The dog flights were spectacular — red mist and helicopters, counter-clockwise or clockwise on demand. I killed at least five at over 500 yards. I will not use the 55 Bergers on Prairie Dogs again since the quest is over. I will use the 40gr V-Maxs and 39gr Sierra BlitzKings for next trip’s 20 BR fodder.

Savage 20BR

CLICK HERE for More Info on Voldoc’s 20 BR Savage Varmint rifle »

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June 24th, 2021

UltimateReloader Video Demonstrates Pistol Case Gauges

Pistol Cartridge Gage Gauge ulimatereloader.com

If you load pistol ammo you should have a case gauge (aka “gage”) for each cartridge type you reload. Caliber-specific, precision-machined cylindrical gauges perform many important functions. They will instantly reveal if your rounds are too long or have excessive headspace. They will also show if your case is bulged or otherwise too fat to chamber easily. You can use the gauge with sized brass as well as loaded rounds.

Case gauges are a “must-have” for anyone loading handgun ammunition, particularly if you crank out large quantities of pistol ammo with a progressive press. An oversize round can cause a misfeed, jam, or other problem. That can ruin your day if you are in the middle of a shooting match. If you are relying on your handgun for self-defense, the last thing you want is a malfunction of any kind. This Editor personally runs every pistol round through a gauge before it goes into the ammo box.

UltimateReloader.com Video Shows How to Use Pistol Case Gauges:

Our friend Gavin Gear of UltimateReloader.com has prepared an excellent video that explains the benefits of pistol case gauges and shows how to use them. Gavin uses the quality gages produced by L.E. Wilson. These are available for the most popular handgun cartridges, both autoloader cartridges, and rimmed revolver cartridges. Gavin demonstrates gage use with .40 SW and .44 magnum cases.

READ Pistol Case Gage ‘How-To’ Guide on UltimateReloader.com

Gavin states: “Using a case gage is very simple, and I would recommend that you add one of these gages to your reloader’s tool chest for each of the pistol cartridge types you reload. It may just save you a lot of time and hassle. Peace of mind is hard to put a price on!”

Ulimate Reloader.com also covers the use of case gauges for rifle cartridges. Rifle cartridge gauges are especially useful in detecting headspace problems. Case gauges can avert many problems, particularly if you reload milsurp rifle brass. CLICK HERE for Rifle Case Gauge “How To” and Video.

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June 21st, 2021

BargainFinder 300: AccurateShooter’s Deals of the Week

AccurateShooter Deals of the Week Weekly Bargain Finder Sale Discount Savings

At the request of our readers, we provide select “Deals of the Week”. Every Sunday afternoon or Monday morning we offer our Best Bargain selections. Here are some of the best deals on firearms, hardware, reloading components, optics, and shooting accessories. Be aware that sale prices are subject to change, and once clearance inventory is sold, it’s gone for good. You snooze you lose.

1. KYGUNCO — Thompson/Center T/CR22 .22LR Rifle, $363.99

22lr rifle sale
Nicely equipped semi-auto .22LR — Good for NRL22 matches

Are you looking to get into the NRL22 discipline but don’t have a rifle to do it with? Check out the Thompson Center T/CR22 .22 LR Rimfire Rifle. This features a 17″ barrel (with front and rear sights) and the stock has a handsome Mossy Oak Camo finish. Equipped with a Picatinny Rail, this is ready to mount a scope for competition. This is a good starter rifle for NRL22 and other tactical rimfire games. Plus it can serve for fun plinking and hunting small varmints.

2. Creedmoor Sports — Kowa 82sv Spotting Scope Packages

Kowa 82sc spotting scope sale
Save $110-$125 on quality spotters with Big 82mm objectives

Having a quality spotting scope is critical for a successful hunt or for reading wind and mirage at a match. One of the absolute best scope for the money is the Kowa 82sv and right now you can take advantage of the Kowa Scope Specials over at Creedmoor Sports. You can pick up the 82sv along with a cover plus your choice of the 25x LER eyepiece or the 20-60x eye piece and be ready for whatever adventure is next on your list.

3. Bullet Central — Berger 7mm 180gr Hybrid Bullets, $63.99

berger 180 hybrid bullet sale
Choice of Champions — Get Berger 7mm 180s while you can

One of the most sought-after match bullets right now is the Berger 7mm/.284 180gr Hybrid Match Bullet. Many vendors are sold out. But we found them in-stock at Bullet Central and ready to ship. Considering the demand, we wouldn’t wait long to order and we’d probably order enough for your upcoming matches this year (including the F-Class Nationals).

4. Amazon — Roll-Up Shooting Mat with Bonus Sand Bag, $34.99

packable shooting mat
Great value, rolls-up into small format, free support sandbag

allen soft case saleTraveling for matches can often mean stripping down to the bare minimum of gear and that usually mean leaving behind large padded shooting mats. A good option instead is a packable shooting mat such as this 78.5″ x 28.5″ Depring folding mat. This mat folds up into a very small footprint making it great for throwing in your checked baggage. FOUR Colors are offered, all priced at $34.99: Tan (shown), OD Green, Black, and Camo. These Depring shooting mats ship with a FREE 6″ x 3.75″ “Unfilled Gun Rest Sand Bag” which can be used for front or rear support.

5. Midsouth — LEE Breech Lock Reloader Press, $41.99

federal .223 .556 ammo
Great deal on compact press with breech lock quick die changes

Every handloader can benefit from a compact, secondary press for decapping at home and/or seating bullets at the range. Weighing under 2.5 pounds, this LEE Breech Lock Reloader Press is easy to transport. The open front design makes it easy to insert/remove cases. This LEE press offers Breech Lock functionality for rapid die changes. With the Breech Lock bushing in place, you can instantly swap dies with a twist of the wrist. Right now this LEE Reloader Press is on sale for $41.99 at Midsouth

6. Natchez — Federal XM193 5.56×45 Ammo 400rds, $399.99

federal .223 .556 ammo
Big savings on CCI 9mm ammo and XM193 ammo for ARs and .223 Rem rifles

Natchez is running a special ammo deal right now. You can save on rifle and pistol ammo AND get FREE SHIPPING. Choose one of three bulk packs: CCI Blazer 9mm 500 rounds for $549.99; or Federal XM193 5.56×45 400 rounds in can for $369.99 ($319.99/400 rds if you buy two cans); or Winchester Lake City M193 5.56×45 1000 rounds in box for $779.99. NOTE: The rifle bulk packs are officially 5.56x45mm ammo, but it should also shoot fine in most modern rifles chambered for .223 Remington. The CCI 9mm and Winchester M193 are priced very competitively, so don’t hesitate.

7. Sportsman’s Warehouse — Allen Soft Rifle Case Sale, 20% OFF

allen soft case sale
Huge selection of soft-side rifle cases on sale starting at $16

You can never have enough protection for your rifles while transporting them which means having a quality soft case. A great place to start is with the Allen soft case sale over at Sportsman’s Warehouse. You’ll find everything from simple single gun cases to deluxe double rifle cases — all at 20% off.

8. MidwayUSA — MTM Pistol Cases, $33.59 aand $44.99

mtm pistol case
Durable, fitted pistol cases for 3 or 6 handguns

Do you find yourself needing to transport several pistols at a time but are tired of having a case for every gun? A handy, affordable solution are the MTM Tactical Pistol Handgun Cases. These fitted cases are offered in different sizes to accommodate 3 to 6 pistols with ease. These can also be locked up to comply with just about any state requirement. They also feature a rubber O-Ring for weather protection.

9. Amazon — Morakniv Fixed Blade Utility Knife, $14.99

utility knife sale
Versatile knife for camping and home, sharp stainless blade

Sometimes you just need a simple, no-nonsense knife in the field that doesn’t cost a lot in case it’s lost or broken. We found this Morakniv Craftline Pro S Fixed Blade Utility Knife which fits the bill exactly. It’s stainless steel, comes with a sheath, and is 3.6″ long making it well-suited for a multitude of cutting tasks. It also makes a good marine safety knife.

10. Amazon — MTM 50rd Deluxe Ammo Carry Box, $11.49

ammo box
Hinged top, bullet tip protection, secure latches

allen soft case saleCarrying 50 rounds of .20 Practical, .222 Rem, .204 Ruger, or .223 Rem/5.56×45 ammunition has never been easier thanks to the MTM H50-RS Deluxe 50-Round Rifle Ammo Case. These stackable MTM ammo boxes feature a strong, durable mechanical hinge. This provides years of use and allows the lid to sit flat. This MTM Deluxe case also has specially designed slots that hold the cartridges in place while protecting the bullet tips. Maximum Overall Cartridge Lenthe is 2.37″ bullet up and 3.45″ bullet down.

These Made-in-USA MTM cases come with a 10-year guarantee. Along with the Green version priced at $11.49, this case is offered in semi-transparent blue for $17.29 on Amazon.

Permalink Bullets, Brass, Ammo, Hot Deals, Optics, Reloading, Tactical 2 Comments »
June 13th, 2021

How to Use a Collet-Type Bullet Puller

Hornady cam-lock bullet puller ammunition UlimateReloader

When you make a reloading mistake, you may need to “pull down” assembled ammo. The embedded UltimateReloader.com video demonstrates how to use the Hornady Cam-Lock bullet pulling system.

When Reloading Goes Bad — The Danger of Over-Charging
Our friend Gavin Gear of UltimateReloader.com was recently reloading some 9mm pistol ammo with his Hornady progressive press. As part of his reloading procedure, he visually checks the cases — and he noticed that the charges seemed high. Sure enough, his most recently-produced rounds were about two grains over spec. He diagnosed the issue: “I was using a powder measure without a baffle. What happened was, over the course of the loading session, things settled in, and the charge level increased.”

Not knowing just when his powder measure started delivering too much powder, Gavin decided, for safety’s sake, to pull down all the ammo he had just reloaded. Yes that’s time-consuming, but it’s better than the alternative — having a dangerous Kaboom while shooting. With fast-burning pistol powders, a two-grain over-charge could cause a blown case, damaged firearm, and/or serious injury.

Watch Cam-Lock Bullet Puller Used to Remove Bullets from Loaded Ammo:

Use of Bullet Puller starts 4:00 minutes into video.

Gavin says it is vitally important to perform safety checks during the reloading process: “You’ve got to do it — check every single round to make sure there IS powder, and that there’s not too MUCH powder. Double, Triple, Quadruple check your components… and your powder charges. You can’t be too careful.”

To pull down a loaded round, first place the cartridge in the shellholder on your press ram. Then raise the round up into the bullet puller device installed where a die would go. The Hornady Cam-lock bullet puller works by clamping the bullet in a collet when you flip down the red-coated lever. Then, with the case held by the rim in the shell-holder, the bullet exits the cartridge as the press ram is lowered. It takes time, but it’s pretty fool-proof once you get the hang of it. This entire process is illustrated in Gavin’s video, starting near the four-minute mark.

Hornady Cam-Lock Bullet puller Gavin Gear Ultimate Reloder.com

The Hornady Cam Lock Bullet Puller has four (4) key components: 1. Cam-Lock die body; 2. Cam-Lock lever; 3. Stem; and 4. Collet (Caliber-specific).

NOTE: In order to use this tool, you’ll need the appropriate collet for each diameter range of bullets you intend to pull. For example use collet #3 for 6mm, collect #6 for 7mm, and collet #7 for .308 Caliber.

Hornady cam-lock bullet puller ammunition UlimateReloader

RCBS Lockout Lock Out die Dillon HornadyRCBS Lock-Out Die
A good safety option for users with progressive presses is the RCBS Lock-Out Die. This has a charge detection rod that dips into each case after powder has dropped. You adjust the die to the proper charge height for your desired load. If the actual dispensed charge is too high or too low, the Lock-Out Die senses the problem and stops the press from advancing to the next case (it does this by preventing the ram/shellplate from fully elevating). We’ve used the Lock-out die with success for both pistol and rifle cartridges. It’s sensitive to about one-half grain with pistol powders.

This Lock-Out Die works with Hornady and Dillon progressives as well as with RCBS progressives. It does take up one die station on the press.

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June 12th, 2021

How to Prep Mil-Surp 5.56 Lake City Brass — Save Money

The U.S. Army Marksmanship Unit regularly publishes a reloading “how-to” article on the USAMU Facebook page. One excellent “Handloading Hump Day” post covered preparation of once-fired 5.56x45mm brass. This article, the first in a 3-part series, has many useful tips. If you shoot a rifle chambered in .223 Rem or 5.56x45mm, this article is worth reading.

This week, Handloading Hump-Day will answer a special request from several competitive shooters who asked about procedures for morphing once-fired GI 5.56mm brass into accurate match brass for NRA High Power Rifle use. The USAMU has used virgin Lake City (LC) 5.56 brass to win National Championships and set National Records for many years. In this 3-part series, we’ll share techniques proven to wring match-winning accuracy from combat-grade brass.

GI brass has an excellent attribute, worth noting — it is virtually indestructible. Due to its NATO-spec hardness, the primer pockets last much longer than most commercial brass when using loads at appropriate pressures.

Preparing Once-Fired GI 5.56 Brass for Reloading (Part 1 of 3)

Assuming our readers will be getting brass once-fired as received from surplus dealers, the following steps can help process the low-cost raw material into reliably accurate components.

1. Clean the Brass
First, clean the brass of any dirt/mud/debris, if applicable. Depending on the brass’s condition, washing it in a soap solution followed by a thorough rinsing may help. [This step also extends the life of the tumbling media.] Approaches range from low-tech, using gallon jugs 1/2 full of water/dish soap plus brass and shaking vigorously, to more high-tech, expensive and time-consuming methods.

cleaning Lake City 5.56 brass

2. Wet-Tumbling Options (Be Sure to Dry the Brass)
When applying the final cleaning/polish, some use tumblers with liquid cleaning media and stainless steel pins for a brilliant shine inside and out, while others take the traditional vibratory tumbler/ground media approach. Degree of case shine is purely personal preference, but the key issue is simple cleanliness to avoid scratching ones’ dies.

If a liquid cleaner is used, be SURE to dry the cases thoroughly to preclude corrosion inside. One method is to dump the wet brass into an old pillow case, then tilt it left/right so the cases re-orient themselves while shifting from corner to corner. Several repetitions, pausing at each corner until water stops draining, will remove most water. They can then be left to air-dry on a towel, or can be dried in a warm (150° F-200° F max) oven for a few minutes to speed evaporation.

Shown below are Lake City cases after cleaning with Stainless Media (STM). Note: STM Case cleaning was done by a third party, not the USAMU, which does not endorse any particular cleaning method.

3. Inspect Every Case
Once dry, inspect each case for significant deformation (i.e., someone stepped on it), damaged mouths/necks and case head/rim damage. Some rifles’ ejectors actually dig small chunks of brass out of the case head — obviously, not ideal for precision shooting. Similarly, some extractors can bend the case rims so badly that distortion is visible when spinning them in one’s fingers. These can be used for plinking, but our match brass should have straight, undamaged rims.

Dented case mouths are common, and these can easily be rounded using a conical, tapered tool, [such as a .223 expander mandrel. A dummy 7.62 or .30-06 cartridge with a FMJ spitzer can also work.] If most of your brass is of one headstamp, this is a good time to cull out any odd cases.

4. Check the Primers Before Decapping
Your clean, dry and inspected brass is now ready for full-length sizing, decapping and re-priming. Historically, primer crimps on GI brass have caused some head-scratching (and vile language) among handloaders. Our next installment will detail efficient, easy and practical methods to remove primer crimp, plus other useful handloading tips. Until next week, Good Shooting!

NOTE: The USAMU Handloading (HL) Shop does not RE-load fired 5.56 brass. We use virgin LC brass with our chosen primer already staked in place. However, our staff has extensive personal experience reloading GI brass for competition, which will supplement the Shop’s customary steps. In handloading, as in life, there are many ways to accomplish any given task. Our suggestions are note presented as the “only way,” by any means. Time for loading/practicing is always at a premium. Readers who have more efficient, alternative methods that maintain top accuracy are invited to share them here.

Accuracy Potential of Mil-Surp 5.56×45 Brass

So, how accurate can previously-fired GI surplus brass be in a good National Match AR-15? Well, here’s a data point from many years ago that might be of interest. A High Power shooter who wrote for the late Precision Shooting magazine took a Bill Wylde-built AR match rifle to a registered Benchrest match. His first 5-round group ever fired in a BR match was officially measured at 0.231″ at 200 hundred yards. This was fired in front of witnesses, while using a moving target backer that confirmed all five rounds were fired.

He recounted that his ammo was loaded progressively with factory 52gr match bullets and a spherical powder using mixed years of LC brass with no special preparation whatsoever. Obviously, this was “exceptional”. However, he had no difficulty obtaining consistent 0.5-0.6 MOA accuracy at 200 yards using LC brass and a generic “practice” load that was not tuned to his rifle.

Saving Money by Using GI Brass

So, with good commercial brass readily available, why would one go to all the extra steps necessary to process fired GI brass? [Editor: It’s about saving money.]

Economically, it makes great sense. When the author was actively practicing and competing with the service rifle, he had ~3,000 rounds of 5.56mm brass, which allowed him to load during winter and spend most time in the summer practicing. If one were wealthy and wanted to shoot nothing but the finest imported brass, the current cost of 3,000 is ~$1920 (plus shipping.)

Dropping down to good, but less-expensive new, U.S. commercial brass brings the price to a much more realistic ~$720. However, at current rates, the same amount of surplus GI once-fired brass costs between $120 — $150, leaving lots of room in the budget for other expenses. [Editor: that’s less than 10% of the cost of the best imported brass.]

Permalink Bullets, Brass, Ammo, Reloading, Tech Tip 1 Comment »
June 4th, 2021

How Cartridge Overall Length (COAL) Affects Pressure & Velocity

Berger Bullets COAL length cartridge

Figure 1. When the bullet is seated farther out of the case, there is more volume available for powder. This enables the cartridge to generate higher muzzle velocity with the same pressure.

Berger Bullets COAL length cartridgeEffects Of Cartridge Over All Length (COAL) And Cartridge Base To Ogive (CBTO) – Part 1
by Bryan Litz for Berger Bullets.
Many shooters are not aware of the dramatic effects that bullet seating depth can have on the pressure and velocity generated by a rifle cartridge. Cartridge Overall Length (COAL) is also a variable that can be used to fine-tune accuracy. It’s also an important consideration for rifles that need to feed rounds through a magazine. In this article, we’ll explore the various effects of COAL, and what choices a shooter can make to maximize the effectiveness of their hand loads.

Sporting Arms and Ammunition Manufacturers’ Institute (SAAMI)
Most loading manuals (including the Berger Manual), present loading data according to SAAMI (Sporting Arms and Ammunition Manufacturers’ Institute) standards. SAAMI provides max pressure, COAL and many other specifications for commercial cartridges so that rifle makers, ammo makers, and hand loaders can standardize their products so they all work together. As we’ll see later in this article, these SAAMI standards are in many cases outdated and can dramatically restrict the performance potential of a cartridge.

Bullet seating depth is an important variable in the accuracy equation. In many cases, the SAAMI-specified COAL is shorter than what a hand loader wants to load their rounds to for accuracy purposes. In the case where a hand loader seats the bullets longer than SAAMI specified COAL, there are some internal ballistic effects that take place which are important to understand.

Effects of Seating Depth / COAL on Pressure and Velocity
The primary effect of loading a cartridge long is that it leaves more internal volume inside the cartridge. This extra internal volume has a well known effect; for a given powder charge, there will be less pressure and less velocity produced because of the extra empty space. Another way to look at this is you have to use more powder to achieve the same pressure and velocity when the bullet is seated out long. In fact, the extra powder you can add to a cartridge with the bullet seated long will allow you to achieve greater velocity at the same pressure than a cartridge with a bullet seated short.

When you think about it, it makes good sense. After all, when you seat the bullet out longer and leave more internal case volume for powder, you’re effectively making the cartridge into a bigger cartridge by increasing the size of the combustion chamber. Figure 1 illustrates the extra volume that’s available for powder when the bullet is seated out long.

Before concluding that it’s a good idea to start seating your bullets longer than SAAMI spec length, there are a few things to consider.

Geometry of a Chamber Throat
The chamber in a rifle will have a certain throat length which will dictate how long a bullet can be loaded. The throat is the forward portion of the chamber that has no rifling. The portion of the bullet’s bearing surface that projects out of the case occupies the throat (see Figure 2).

Berger Bullets COAL length cartridge

The length of the throat determines how much of the bullet can stick out of the case. When a cartridge is chambered and the bullet encounters the beginning of the rifling, known as the lands, it’s met with hard resistance. This COAL marks the maximum length that a bullet can be seated. When a bullet is seated out to contact the lands, its initial forward motion during ignition is immediately resisted by an engraving force.

Seating a bullet against the lands causes pressures to be elevated noticeably higher than if the bullet were seated just a few thousandths of an inch off the lands.

A very common practice in precision reloading is to establish the COAL for a bullet that’s seated to touch the lands. This is a reference length that the hand loader works from when searching for the optimal seating depth for precision. Many times, the best seating depth is with the bullet touching or very near the lands. However, in some rifles, the best seating depth might be 0.100″ or more off the lands. This is simply a variable the hand loader uses to tune the precision of a rifle.

CLICK HERE to Read Full Article with More Info

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June 1st, 2021

Million-Round Turret Press — This Redding T-7 Has Done Its Duty

Redding T-7 Turret reloading press ammo ammunition

Here’s something you don’t see every day — a reloading press that has loaded over 1,000,000 rounds of ammo. At the NRA Convention in Dallas in 2018, Redding showcased an old Redding T-7 Turret Press delivered to Sierra Bullets decades ago. 0ne of the very first T-7s made by Redding, this “old warrior” was used by Sierra Bullets to load over 1,000,000 rounds of ammunition in Sierra’s ballistics lab.


Redding T-7 Turret reloading press ammo ammunitionRedding T-7 Still Within Spec
After all that loading, Redding tested the press and, remarkably, found that it still remained “within spec”. Redding notes: “This press was subjected to real world reloading wear and stress yet remains within ‘new’ spec after this historic test”. When showcased in Dallas, this Redding turret press was fitted with indicators to show “just how good American steel and craftsmanship remains after what, in a normal situation, would represent numerous lifetimes of use.”

The Redding T-7 now has major turret press rivals — the Lyman All-American 8-station press, and the Area 419 9-station ZERO Turret Press. That $1200 ZERO Turret is generally regarded as the most sophisticated turret press ever created.

Redding T-7 Turret reloading press ammo ammunitionAbout Redding Reloading
Redding Reloading Equipment has crafted quality, American-made products for the precision handloading market since 1946. Along with single-stage and turret presses, Redding makes great dies. And Redding’s line of tools/accessories includes concentricity gauges, scales, trimmers, powder measures, powder tricklers, cleaning tools, deburring tools, bushings, and many other quality items.

To learn more about Redding products or to download the 2021 Redding catalog visit Redding-Reloading.com. You can also request a free 2021 printed catalog.

Permalink Bullets, Brass, Ammo, Gear Review, Reloading 1 Comment »
June 1st, 2021

Go with the “O” — O-Rings May Reduce Run-Out When Sizing

reloading die O-ring
reloading die O-ring

Here’s an inexpensive procedure that can help you load straighter ammo, with slightly better measured concentricity (i.e. less run-out) on the case necks and bullets. Simply use a Rubber O-Ring on the underside of the die locking ring. This allows the die to self-align itself (slightly) to the case that is being sized. Without the O-Ring, if the flat surface on the top of your press is not perfectly square with the thread axis, your die can end up slightly off-angle. This happens when the bottom of the locking ring butts up tight against the top of the press. The O-Ring allows the die to float slightly, and that may, in turn, reduce the amount of run-out induced during case sizing.

Top prone shooter GSArizona has tried this trick and he says it works: “Go to your local hardware store and get a #17 O-Ring (that’s the designation at Ace Hardware, don’t know if its universal). Slip the O-Ring on the die and re-adjust the lock ring so that the O-Ring is slightly compressed when the die is at the correct height. Size and measure a few more cases. You will probably see a slight improvement in neck concentricity as the die can now float a bit as the case enters and leaves it. This isn’t going to be a dramatic improvement, but it’s a positive one.”

We want to stress that adding O-Rings to sizing dies may help some reloaders, but we don’t offer this as a panacea. Try it — if using the O-Ring reduces measured runout that’s great. If it doesn’t, you’ve only spent a few pennies to experiment.

reloading die O-ring

Lee Precision makes die lock rings with built-in O-Rings. Lee’s distinctive lock ring design allows the same kind of self-alignment, which is good. However, Lee lock rings don’t clamp in place on the die threads, so they can move when you insert or remove the dies — and that can throw off your die setting slightly. By using an O-Ring under a conventional die lock ring (that can be locked in place), you get the advantages of the Lee design, without the risk of the lock ring moving.

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May 29th, 2021

Frankford Deprimer Tool — Deprime Cases without a Press

Frankford Arsenal deprimer depriming hand tool decapping primer removal

Many shooters prefer to deprime their brass before resizing. That way they can tumble cases or keep primer debris off their main press. To deprime cases before sizing or cleaning you can use a Depriming Die (aka “decapping die”). This pushes out the spent primer without changing the neck or body of a case. Such decapping dies work fine, but they do require the use of a press. Here is a handy alternative — a cool tool that allows you to deprime brass anywhere — no press needed.

Handheld Primer Removal Tool From Frankford Arsenal
This cleverly-designed Hand Deprimer Tool allows you to deprime cartridge cases without a press. This hand-tool from Frankford Arsenal will deprime brass and capture primers conveniently. You can deprime your cases while watching TV or relaxing in your favorite chair.

Frankford Arsenal deprimer depriming hand tool decapping primer removal

This device lets you remove spent primers anywhere — no press needed and all the mess (cups/anvils/residue) stays in the capture chamber. This tool comes works with nearly all common case types up to .338 Lapua Magnum. With good leverage, this tool does the job quicklyi and efficiently. Forum members have praised this handy tool, but recommend wearing a thick glove if doing more than 100 cases in a sesssion.

Frankford Arsenal deprimer depriming hand tool decapping primer removal

This handy depriming tool is very versatile. With a universal, cylinder-style cartridge-holder, the tool can deprime a wide variety of cartridge types from .20 caliber up to .338 caliber. Three different plastic collets are provided to handle for different diameter cases. Spent primers are captured in a removable spent primer catch tube. Simply twist off the clear catch tube to dump the spent primers. With die-cast metal construction, this tool should last through many thousands of depriming cycles. MSRP is $54.99. Right now it is $44.99 on Amazon with 82% 5-star ratings.

User Modifications — Grip Padding and High-Volume Capture

Many users recommended putting some kind of padding on the grip and front lever to reduce pressure on the fingers. This can be done with a wrap or a rubber covering. In addition, users have adapted the unit with an attached hose and large primer capture jug. If you depriming hundreds of cases at a time, this hose conversion may make sense.

Frankford Arsenal deprimer depriming hand tool decapping primer removal

Frankford Arsenal deprimer depriming hand tool decapping primer removal

Review from actual owner: “I have owned one of these for about eight years and deprimed over 10,000 cases with this tool. I have never had to replace a single part on it. You will have to adjust the return spring every so often, but that is a very easy task. If you are depriming a LOT of brass, the handle can tear up your hand a bit. Solution: Wear a Mechanics Glove. Easy Peasy! You will NOT regret this purchase.”

How to Adapt Tool for Small Flash Hole Brass
The Frankford Arsenal Deprimer Tool was designed for LARGE flash-hole brass. To deprime brass with small (1.5mm/0.59″) small flash-holes, as found on Lapua .220 Russian and 6mmBR cases, you will need to reduce the pin diameter. A smaller pin is “in development” according to the manufacturer. Frankford Arsenal currently recommends purchasing a replacement pin and “sanding it down” to the smaller diameter. NOTE: This is NOT difficult — simply spin the stock pin in some sandpaper.

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May 29th, 2021

Six Tips for Success at Local Fun Matches

Varmint silhouette fun match

Summer’s almost here! Every summer weekend, there are hundreds of local club “fun matches” conducted around the country. One of the good things about club shoots is that you don’t have to spend a fortune on equipment to have fun. But we’ve seen that many club shooters handicap themselves with a few common equipment oversights or lack of attention to detail while reloading. Here are SIX TIPS that can help you avoid these common mistakes, and build more accurate ammo for your club matches.

Benchrest rear bag1. Align Front Rest and Rear Bag
We see many shooters whose rear bag is angled left or right relative to the bore axis. This can happen when you rush your set-up. But even if you set the gun up carefully, the rear bag can twist due to recoil or the way your arm contacts the bag. After every shot, make sure your rear bag is aligned properly (this is especially important for bag squeezers who may actually pull the bag out of alignment as they squeeze).

Forum member ArtB adds: “To align my front rest and rear bag with the target, I use an old golf club shaft. I run it from my front rest stop through a line that crosses over my speed screw and into the slot between the two ears. I stand behind that set-up and make sure I see a straight line pointing at the target. I also have a piece of tape that I’ve placed on the golf shaft that indicates how far the back end of the rear bag should be placed from the front rest stop.”

2. Avoid Contact Interference
We see three common kinds of contact or mechanical interference that can really hurt accuracy. First, if your stock has front and/or rear sling swivels make sure these do NOT contact the front or rear bags at any point of the gun’s travel. When a sling swivel digs into the front bag that can cause a shot to pop high or low. To avoid this, reposition the rifle so the swivels don’t contact the bags or simply remove the swivels before your match. Second, watch out for the rear of the stock grip area. Make sure this is not resting on the bag as you fire and that it can’t come back to contact the bag during recoil. That lip or edge at the bottom of the grip can cause problems when it contacts the rear bag. Third, watch out for the stud or arm on the front rest that limits forward stock travel. With some rests this is high enough that it can actually contact the barrel. We encountered one shooter recently who was complaining about “vertical flyers” during his match. It turns out his barrel was actually hitting the front stop! With most front rests you can either lower the stop or twist the arm to the left or right so it won’t contact the barrel.

varmint fun match groundhog

3. Weigh Your Charges — Every One
This may sound obvious, but many folks still rely on a powder measure. Yes we know that most short-range BR shooters throw their charges without weighing, but if you’re going to pre-load for a club match there is no reason NOT to weigh your charges. You may be surprised at how inconsistent your powder measure actually is. One of our testers was recently throwing H4198 charges from a mechanical measure for his 30BR. Each charge was then weighed twice with a Denver Instrument lab scale. Our tester found that thrown charges varied by up to 0.7 grains! And that’s with a premium measure.

4. Measure Your Loaded Ammo — After Bullet Seating
Even if you’ve checked your brass and bullets prior to assembling your ammo, we recommend that you weigh your loaded rounds and measure them from base of case to bullet ogive using a comparator. If you find a round that is “way off” in weight or more than .005″ off your intended base to ogive length, set it aside and use that round for a fouler. (Note: if the weight is off by more than 6 or 7 grains you may want to disassemble the round and check your powder charge.) With premium, pre-sorted bullets, we’ve found that we can keep 95% of loaded rounds within a range of .002″, measuring from base (of case) to ogive. Now, with some lots of bullets, you just can’t keep things within .002″, but you should still measure each loaded match round to ensure you don’t have some cases that are way too short or way too long.

Scope Ring5. Check Your Fasteners
Before a match you need to double-check your scope rings or iron sight mounts to ensure everything is tight. Likewise, you should check the tension on the screws/bolts that hold the action in place. Even with a low-recoiling rimfire rifle, action screws or scope rings can come loose during normal shooting.

6. Make a Checklist and Pack the Night Before
Ever drive 50 miles to a match then discover you have the wrong ammo or that you forgot your bolt? Well, mistakes like that happen to the best of us. You can avoid these oversights (and reduce stress at matches) by making a checklist of all the stuff you need. Organize your firearms, range kit, ammo box, and shooting accessories the night before the match. And, like a good Boy Scout, “be prepared”. Bring a jacket and hat if it might be cold. If you have windflags, bring them (even if you’re not sure the rules allow them). Bring spare batteries, and it’s wise to bring a spare rifle and ammo for it. If you have just one gun, a simple mechanical breakdown (such as a broken firing pin) can ruin your whole weekend.

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May 26th, 2021

Build Your Own Portable Reloading Station with B&D Workmate

portable reloading benchA while back, we featured a portable reloading bench built on a Black & Decker Workmate. That proved a VERY popular do-it-yourself project so we’re showing it again, in case you missed it the first time.

Texan Robert Lewis made himself a great portable reloading bench from plywood mounted to a Black & Decker Workmate. The bench, roughly 22″ x 19″ on top, folds up to fit easily in your car’s trunk or behind the seats in a pick-up truck cab. Four recessed bolts hold the wood top section to the collapsible B&D Workmate. The sides and back of the unit are attached to the base with small nails. There is a small shelf (also nailed in place) which can be used to clamp a powder measure or hold a scale. Shown in the photo is a Harrell’s Benchrest measure and Harrell’s single-stage “C” press.

Click for Detail of Top.
portable shooting bench

The whole unit can be built for about $65.00 with pine, or $80.00 with oak (as shown). Robert explained: “The Workmate was $40. If someone bought a 2’x4′ sheet of 3/4″ oak plywood, I think it is around $30. Using pine plywood would be about half that. Fasteners were $3. Spar Urethane would be $5.”

Robert told us: “I used a couple ideas I found on the web. The Larry Willis website gave me the idea to use the Black and Decker Workmate as a base. I found the Workmate on sale for $40 and the top is made from oak plywood I had in my shop. I sealed the wood with three coats of Spar Urethane. The whole thing folds into a nice package for transportation to and from the range.”

NOTE: Since we first ran this story, the price of a Black & Decker Workmate WM225 has increased. However you can still pick a WM225 Workmate for under $60.00. Amazon is currently selling WM225 Workmates for $59.58. The next best price we found was $69.61 at Home Depot, still a good price (Lowe’s is charging $94.98).

Click HERE for FREE WORKBENCH PLANS.

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April 22nd, 2021

AR, Garand, M1A — Six Rules for Semi-Auto Gas Gun Reloading

Reloading for Service Rifles
SFC Lance Dement as featured in CMP’s First Shot Online.

The U.S. Army Marksmanship Unit (USAMU) has published a great series of reloading “how-to” articles on its Facebook Page. This post covers key factors to consider when loading ammunition for Match Rifles and Service Rifles, with a particular focus on self-loading “gas guns”. Visit the USAMU Facebook Page each Wednesday for other, helpful “Handloading Hump-Day” tips.

We offer some “cardinal rules” to help new gas-gun handloaders with safety and efficiency. These address both Match Rifle and Service Rifle versions of the AR15, M1 Garand, M1A, and M110. However, they can also improve safe reloading for many other auto-loaders such as M1 Carbines, FALs, SIGs, etc. The author distilled these principles many years ago to help focus on the essential aspects of these rifles.

RULE ONE: Service Rifles Are Not Benchrest Rifles
Gas-guns require a relatively loose fit between ammunition and chamber (vs. bolt actions) for safe, smooth operation. Many techniques, such as neck sizing and keeping cartridge headspace quite tight, are popular in the extreme bolt gun accuracy realm. However, they are of little value with Service Rifles, and some could even be hazardous. Before adopting a specialized technique, seriously consider whether it is appropriate and beneficial in a gas-gun.

RULE TWO: Never Compromise Safety to Obtain Accuracy
Example: If choosing a brand of great, but ultra-sensitive match primers offers possibly better accuracy at the risk of slam-fires in your design of rifle, don’t do it! You are issued exactly two eyes and ten fingers (best-case scenario). Risking them trying to squeeze 0.25 MOA better accuracy out of an M1A, etc. simply isn’t worth it.

Reloading for Service Rifles

RULE THREE: Tailor the Precision to Your Individual Skill and Your Rifle’s Potential
This has been addressed here before, but bears repeating for newcomers. If you are struggling to break out of the Marksman Class, or using a CMP M1 “As-Issued,” then laboriously turning the necks of your 600-yard brass is a waste of time. Your scores will improve much faster by practicing or dry-firing. On the other hand, if the reigning champions anxiously check your scores each time you fire an event, a little neck-turning might not be so far-fetched.

Verifying Load Improvements — Accuracy hand-loading involves a wide variety of techniques, ranging from basic to rather precise. Carefully select those which offer a good return on investment for your time and labor. In doubt? Do a classic pilot study. Prepare ammo for at least three or four ten-shot groups with your new technique, vs. the same with your standard ammo. Then, pick a calm day and test the ammo as carefully as possible at its full distance (e.g. 200, 300, or 600 yards) to verify a significant improvement. A little testing can save much labor!

RULE FOUR: Be Your Own Efficiency Expert
Serious Service Rifle shooters generally think of ammunition in terms of thousands of rounds, not “boxes”, or even “hundreds”. Analyze, and WRITE DOWN each step in your reloading process. Count the number of times each case is handled. Then, see if any operations can be dropped or changed without reducing safety or accuracy. Eliminating just two operations saves 2000 steps per 1000 rounds loaded. Conversely, carefully consider any measurable benefits before adding a step to your routine.

RULE FIVE: In Searching for Greater Accuracy with Efficiency, Look for System Changes
For example, instead of marking your 300-yard rounds individually to differentiate them from your 200-yard ammo, would a simple change in primers work? If accuracy is maintained, using brass-colored primers for 200 and silver for 300 provides an indelible indicator and eliminates a step! Similarly, rather than spending hours selecting GI surplus brass for weight and neck uniformity, consider splurging on some known, high-quality imported match brass for your 600-yard loads. Results should be excellent, time is saved, and given limited shooting at 600 yards, brass life should be long.

RULE SIX: Check All Your Primers Before Packaging Your Loaded Ammo
This seems simple and even intuitive. However, many slam-fires (which were much more common when M1s and M1As were the standard) are due, at least in part, to “high” primers. Primers should be seated below flush with the case head. The USAMU has addressed this at length in a previous column, but each round should be checked for properly-seated primers before they are packaged for use.

Reloading for Service Rifles

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April 16th, 2021

How Bullet Bearing Surface Length Can Affect Load Pressure

USAMU Bullet Ogive Comparison Safety Reloading
Three near-equal-weight 7mm bullets with different shapes and bearing surface.

This article, from the USAMU Facebook Page, concerns reloading safety. In the relentless quest for more speed and flatter ballistics, some hand-loaders load way too hot, running charges that exceed safe pressure levels. Hint: If you need a mallet to open your bolt, chances are your load is too hot. Stay within safe margins — your equipment will last longer, and you won’t risk an injury caused by over-pressure. In this article, the USAMU explains that you need to account for bullet shape, diameter, and bearing surface when working up a load. Don’t assume that a load which is safe for one bullet will be safe for another even if both bullets are exactly the same weight.

USAMU Reloading tips Army Marksmanship

Today, we continue our handloading safety theme, focusing on not inadvertently exceeding the boundaries of known, safe data. Bullet manufacturers’ loading manuals often display three, four, or more similar-weight bullets grouped together with one set of load recipes. The manufacturer has tested these bullets and developed safe data for that group. However, seeing data in this format can tempt loaders — especially new ones — to think that ALL bullets of a given weight and caliber can interchangeably use the same load data. Actually, not so much.

USAMU Bullet Ogive Comparison Safety Reloading

The researchers ensure their data is safe with the bullet yielding the highest pressure. Thus, all others in that group should produce equal or less pressure, and they are safe using this data.

However, bullet designs include many variables such as different bearing surface lengths, hardness, and even slight variations in diameter. In fact, diameters can occasionally range up to 0.001″ by design. Thus, choosing untested bullets of the same weight and caliber, and using them with data not developed for them can yield excess pressures.

This is only one of the countless reasons not to begin at or very near the highest pressure loads during load development. Always begin at the starting load and look for pressure signs as one increases powder charges.

Bullet Bearing Surface and Pressure
Bullet bearing surface length (BSL) is often overlooked when considering maximum safe powder charges and pressures. In Photo 1, note the differences in the bullets’ appearance. All three are 7 mm, and their maximum weight difference is just five grains. Yet, the traditional round nose, flat base design on the left appears to have much more BSL than the sleeker match bullets. All things being equal, based on appearance, the RN/FB bullet seems likely to reach maximum pressure with significantly less powder than the other two designs.

TECH TIP: Bullets of the same weight (and caliber) can generate very different pressure levels due to variances in Bearing Surface Length (BSL).

USAMU Bullet Ogive Comparison Safety ReloadingBullet 1 (L-R), the RN/FB, has a very slight taper and only reaches its full diameter (0.284 inch) very near the cannelure. This taper is often seen on similar bullets; it helps reduce pressures with good accuracy. The calculated BSL of Bullet 1 was ~0.324″. The BSL of Bullet 2, in the center, was ~0.430″, and Bullet 3’s was ~ 0.463″. Obviously, bullets can be visually deceiving as to BSL!

Some might be tempted to use a bullet ogive comparator (or two) to measure bullets’ true BSL for comparison’s sake. Unfortunately, comparators don’t typically measure maximum bullet diameter and this approach can be deluding.

Note: Due to time constraints, the writer used an approximate, direct measurement approach to assess the bullets’ different BSLs. While fairly repeatable, the results were far from ballistics engineer-grade. Still, they are adequate for this example.

Photo 2: The Perils of Measuring Bearing Surface Length with Comparators
USAMU Bullet Ogive Comparision Safety Reloading

In Photo 2, two 7mm comparators have been installed on a dial caliper in an attempt to measure BSL. Using this approach, the BSLs differed sharply from the original [measurements]. The comparator-measured Bullet 1 BSL was 0.694” vs. 0.324” (original), Bullet 2 was 0.601” (comparator) vs. 0.430” (original), and Bullet 3 (shown in Photo 2) was 0.602” (comparator) vs. 0.463” (original). [Editor’s comment — Note the very large difference for Bullet 1, masking the fact that the true full diameter on this bullet starts very far back. You can use comparators on calipers, but be aware that this method may give you deceptive reading — we’ve seen variances just by reversing the comparators on the calipers, because the comparators, typically, are not perfectly round, nor are they machined to precision tolerances.]

Thanks to the U.S. Army Marksmanship Unit for allowing the reprint of this article.

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March 30th, 2021

Know Your Terminology — CUP vs. PSI

SAAMI CUP PSI Cartridge Copper Units Pressure PSI
Image by ModernArms, Creative Common License.

by Philip Mahin, Sierra Bullets Ballistic Technician
This article first appeared in the Sierra Bullets Blog

If you asked a group of shooters to explain the difference between CUP and PSI, the majority would probably not be able to give a precise answer. But, for safety reasons, it’s very important that all hand-loaders understand these important terms and how they express cartridge pressures.

The ANSI / SAAMI group, short for “American National Standard Institute” and “Sporting Arms and Ammunition Manufacturers’ Institute”, have made available some time back the voluntary industry performance standards for pressure and velocity of centerfire rifle sporting ammunition for the use of commercial manufacturers. [These standards for] individual cartridges [include] the velocity on the basis of the nominal mean velocity from each, the maximum average pressure (MAP) for each, and cartridge and chamber drawings with dimensions included. The cartridge drawings can be seen by searching the internet and using the phrase ‘308 SAAMI’ will get you the .308 Winchester in PDF form. What I really wanted to discuss today was the differences between the two accepted methods of obtaining pressure listings. The Pounds per Square Inch (PSI) and the older Copper Units of Pressure (CUP) version can both be found in the PDF pamphlet.

SAAMI CUP PSI Cartridge Copper Units Pressure PSICUP Pressure Measurement
The CUP system uses a copper crush cylinder which is compressed by a piston fitted to a piston hole into the chamber of the test barrel. Pressure generated by the burning propellant causes the piston to move and compress the copper cylinder. This will give it a specific measurable size that can be compared to a set standard. At right is a photo of a case that was used in this method and you can see the ring left by the piston hole.

PSI Pressure Measurement
What the book lists as the preferred method is the PSI (pounds per square inch or, more accurately, pound-force per square inch) version using a piezoelectric transducer system with the transducer flush mounted in the chamber of the test barrel. Pressure developed by the burning propellant pushes on the transducer through the case wall causing it to deflect and make a measurable electric charge.

Q: Is there a standardized correlation or mathematical conversion ratio between CUP and PSI values?
Mahin: As far as I can tell (and anyone else can tell me) … there is no [standard conversion ratio or] correlation between them. An example of this is the .223 Remington cartridge that lists a MAP of 52,000 CUP / 55,000 PSI but a .308 Winchester lists a 52,000 CUP / 62,000 PSI and a 30-30 lists a 38,000 CUP / 42,000 PSI. It leaves me scratching my head also but it is what it is. The two different methods will show up in listed powder data[.]

So the question on most of your minds is what does my favorite pet load give for pressure? The truth is the only way to know for sure is to get the specialized equipment and test your own components but this is going to be way out of reach for the average shooter, myself included. The reality is that as long as you are using printed data and working up from a safe start load within it, you should be under the listed MAP and have no reason for concern. Being specific in your components and going to the load data representing the bullet from a specific cartridge will help get you safe accuracy. [With a .308 Winchester] if you are to use the 1% rule and work up [from a starting load] in 0.4 grain increments, you should be able to find an accuracy load that will suit your needs without seeing pressure signs doing it. This is a key to component longevity and is the same thing we advise [via our customer service lines] every day. Till next time, be safe and enjoy your shooting.

SAAMI CUP PSI Cartridge Copper Units Pressure PSI

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