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October 7th, 2018

Darrell Holland Upgrade for RCBS Bench Priming Tool

Priming Tool Holland Perfect RCBS bench mount primer

Gunsmith Darrell Holland sells a priming tool that upgrades the RCBS Auto Bench Priming Tool with key features — including primer seating depth control. If your hand starts to hurt after priming dozens of cases with a hand-held, squeeze-type priming tool, you may want to consider Holland’s invention, which he calls the “Perfect Primer Seater” (PPS).

Holland basically has modified the RCBS lever, adding a precise crush control and a means of measuring depth with a gauge. He claims this gives “an EXACT primer seating depth based on primer pocket depth and primer thickness”. With Holland’s PPS, primer seating depth is controlled with a rotating wheel that limits lever travel in precise gradations. You can buy the complete priming system for $215.00, or, if you already own the RCBS Auto Prime tool, you can purchase an adapter kit (with base, arm, adjuster, and gauge etc.) for $120.00. To order, visit Hollandguns.com. Click on “Reloading Equipment”, and look for the Perfect Primer Seater. Scroll down to the bottom of the page to add items to the shopping cart.

Priming Tool Holland Perfect RCBS bench mount primer

Priming Tool Holland Perfect RCBS bench mount primerUser Review by Tommy Todd
Sierra Bullets’ Chief Ballistician Tommy Todd acquired the Holland Perfect Primer Seater, and gave it a positive review. Todd writes: “This cartridge case priming system allows you to measure the primer pocket depth and adjust the seating tool to match the primer seating depth for a contact fit with a measured lot of primers to the cases you are working with. Mr. Darrell Holland has taken a standard RCBS automatic bench-mounted priming tool and modified it to a new level of precision. The modifications allow you to measure the primer pocket depth, primer height, and with the addition of an adjustable stop on the priming tool achieve precision primer seating, rather than how the primer ‘feels'[.]

If you are already utilizing the RCBS priming tool, Mr. Holland offers an adapter kit to upgrade your equipment. If you are looking for a new priming unit, I suggest giving this product a try. Increasing consistency when seating primers should result in smaller groups[.]”

Permalink Bullets, Brass, Ammo, Gear Review, Reloading 4 Comments »
October 6th, 2018

Case Prep Tips from Western Powders

Western Powders Case Preparation prep inspection flash holes primer pockets reloading

Western Powders (which sells Accurate, Ramshot, and Norma powders) has published an article on case inspection and preparation. There are many tips in this article that can be useful to precision hand-loaders. For example, every time you open a new box of cartridge brass (particularly from domestic makers), you should inspect each case for flaws.

TIP ONE: Visual Inspection — Finding Flaws
Cases are mass-produced items and malformed ones are relatively common. Inspect each case carefully looking for obvious defects. A bench-mounted magnifying glass with light is a real help for the over-40 crowd. The main defects will be cracks in the neck or case body, crushed shoulders or deep creases in the neck. Next check the primer pocket. It is also fairly common to find flash holes that are damaged or, more rarely, not concentric to the primer pocket.

Western Powders Case Preparation prep inspection flash holes primer pockets reloading

Imperfections like small dings in the case body, or necks that are not completely symmetrical do not have to be eliminated at this step. Damage of this sort is usually from loose packaging and usually has not seriously damaged the brass. [Running an expander mandrel in the neck] and fire-forming will iron out these largely cosmetic issues.

The Western Powder article also talks about primer pocket uniforming. We do NOT normally uniform the pockets for Lapua or RWS brass from the start. However, pocket uniforming can be beneficial with some other brands of brass, including Lake City, Remington, and Winchester. If you shoot milsurp brass, set time aside for pocket uniforming.

TIP TWO: Primer Pocket Uniforming
Western Powders Case Preparation inspection flash holes primer pockets reloadingLike flash holes, primer pockets are mass-produced and prone to small dimensional changes. A uniforming tool is used to make the depth of each primer pocket consistent. In turn this allows similar firing pin strike depths on the primer which creates more consistent ignition characteristics.

A good uniforming tool should have a shoulder, or another positive stop, that sets the cutter’s depth. Its use is pretty straightforward. The cutter is inserted into the pocket and turned clockwise several times until the stop in flush with the case head and no more brass is removed from the juncture of the pocket’s base and sidewall. This a job best done by hand. You will feel when the cutting is finished by a change in how smoothly the cutter turns in the pocket. Very little material is actually removed; usually just enough to square the radius at the bottom of the pocket.


READ Full Case Prep Article in Western Powders Blog »

Western Powders Blog Case Prep Neck turning

Permalink Bullets, Brass, Ammo, Reloading No Comments »
October 5th, 2018

Mount Press ABOVE Your Bench with Bench Topper

Berry's Bench Topper Reloading Platform
Berry’s unique, all-metal Bench Topper lets you place a reloading press above your bench surface, clearing valuable space in your reloading area.

The Bench Topper, from Berry’s Manufacturing, is a sturdy platform that holds a loading press and storage bins in a raised position above your bench — effectively creating additional room for scales, trimmers, and component storage below. The $114.66 Bench Topper (Midsouth item 037-00191) can bolted to your bench, or it can be secured with C-Clamps (for easy removal). Do you load at the range? The Bench Topper can be easily transported in your vehicle, providing a handy platform for your press and powder measure.

Bench Topper Specs:

Top Plate:
6 x 20 x 1/4″

Bottom Plate:
10 x 20 x 1/4″

Height: 11.5 Inches

Weight: 12.5 Pounds

Berry’s Bench Topper is crafted from CNC-machined aluminum and powder-coated black for durability. It comes with two aluminum hangers for storage bins for bullets or brass. All fasteners are recessed for a clean work surface. NOTE: The Bench Topper must be assembled by the purchaser, and YOU MUST DRILL YOUR OWN HOLES for installation of your press or other hardware. This requires a few minutes of initial set-up time, but this allows a secure, custom installation for any brand of reloading press.

Product Tip from EdLongrange. We welcome user submissions.
Permalink Gear Review 2 Comments »
October 2nd, 2018

Bump Control: Precision Shims for Full-Length Sizing Dies

Sinclair Die Shims

When your cases become hard to extract, or you feel a stiff bolt lift when removing a cartridge, it’s probably time to full-length size your cases, and “bump” the shoulder back. With a hunting load, shoulder bumping may only be required every 4-5 loading cycles. Short-range benchrest shooters, running higher pressures, typically full-length size every load cycle, bumping the shoulder .001-.002″. High Power shooters with gas guns generally full-length size every time, and may need to bump the shoulders .003″ or more to ensure reliable feeding and extraction.

Use Shims for Precise Control of Shoulder Bump
Some shooters like to set the “default” position for their full-length die to have an “ample” .003″ or .004″ shoulder bump. When they need less bump, a simple way to reduce the amount of shoulder movement is to use precision shims in .001″ (one-thousandth) increments.

Here are reports from Forum members who use the shims:

“Great product. I have my die lock ring(s) adjusted for the shortest headspace length on my multiple chambers 6BRs and 6PPCs. When needing a longer headspace, I just refer to my notes and add the appropriate shim under the lock ring. Keep it simple.” — F.D. Shuster

Mats Johansson writes: “I’ve been using [shims] since Skip Otto (of BR fame) came out with them. I set up my dies with the .006″ shim, giving me the option of bumping the shoulder a bit more when the brass gets old and hardens while still having room to adjust up for zero headspace, should I have missed the original setup by a thou or two. Hunting rounds can easily be bumped an extra .002-.003″ for positive, no-crush feeding. Being a safety-oriented cheapskate, I couldn’t live without them — they let me reload my cases a gazillion times without dangerous web-stretching. Shims are a must-have, as simple as that.” — Mats Johansson

Sinclair Die ShimsSinclair Int’l offers a seven-piece set of Sizing Die Shims that let you adjust the height of your die (and thereby the amount of bump and sizing) in precise .001″ increments. Sinclair explains: “Some handloaders will set their die up to achieve maximum sizing and then progressively use Sinclair Die Shims between the lock ring and the press head to move the die away from the shellholder. Doing this allows you to leave the lock ring in the same position. These shims are usually available in increments of .001″ and work very well.”

Seven Shims from .003″ to .010″
Sinclair’s Die Shim Kit (item 22400) includes seven shims in thicknesses of .003, .004, .005, .006, .007, .008, and .010. For ease of use, shim thickness is indicated by the number of notches cut in the outer edge of each shim. Even without looking you can “count” the notches by feel. Normally priced at $11.99, this shim kit is on sale now for $10.99.

Permalink Bullets, Brass, Ammo, Reloading 1 Comment »
September 24th, 2018

Bargain Finder 157: AccurateShooter’s Deals of the Week

Accurateshooter Bargain Finder Deals of Week

At the request of our readers, we provide select “Deals of the Week”. Every 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. Natchez — Rock Chucker Supreme Reloading Kit, $279.99

Deals of Week RCBS Rock Chucker Supreme Kit

Everything you see above can be yours for just $279.99. Great Deal. Right now, Natchez is selling the Rock Chucker Supreme Master Reloading Kit for $279.99, a great price considering all the hardware you get: Press, Primer Tool, Scale, Powder Measure, Loading Tray, Reloading Manual and more. Heck, the Rock Chucker press alone is worth $160.00+. This is good starter kit for any reloader with sturdy items (like the Rock Chucker press), that will last a lifetime.

2. Natchez — FREE HazMat on Orders of $99.99 or more

Here’s a very attractive promotion if you need powder and/or primers. Right now Natchez is offering FREE HazMat for orders of $99.99 or more. This can save you $25-$40 on the delivered cost of your order. NOTE: Act soon — this deal expires 9/26/2018 at 11:59 PM and you must use CODE FH180924.

Credit EdLongrange for this tip. He notes: “Natchez … was somewhat vague as to whether you need to get $99.99 of the same product, so I added one each of two different primers and two different powders and the code worked. Natchez has … excellent prices on Federal Gold Medal Match primers, including what used to be really-hard-to-get GM215M.” ORDER HERE.

3. Brownells — Howa .308 Win Full Camo with Scope $652.99

Brownells Howa Hunting rifle kryptec Camo Nikko scope bargain deal hydrodipped

The Howa 1500 Full-Dip Kryptek rifle is purpose-built for hunters who want a full matching camo rifle and scope. This .308 Winchester rig features a pillar-bedded Howa action with 20″ barrel in a quality Hogue stock. On top is a Nikko 4-16x44mm scope with one-inch tube. The entire rifle and scope features a hydro-dipped Kryptek Highlander camo finish which is handsome AND very effective in the field. NOTE: The current Sale Price is $662.99. Use CODE M8Y to save $10 and get FREE Shipping. That lowers your delivered price to $652.99, which includes the Nikko 4-16X scope. All-up weight, with scope, is 10 pounds. Sorry this deal is not currently available in other chamberings — .308 Win only.

4. Amazon — Nikon FX1000 6-24x56mm SFP Scope, $599.99

Amazon nikon X1000 Black scope MOA Mrad SFP second focal plane

We’ve checked out the Nikon Black X1000 series scopes and they offer a lot of performance for the price. On sale now at Amazon for just $599.99 is the second focal plane (SFP) BLACK X1000 6-24x50mm model with X-MOA reticle. A Mil version with 0.1 Mil click and X-MRAD reticle is also available for $646.99. These scopes have very crisp controls and great glass for the money. The MOA version 1/4-MOA click with 12 MOA per revolution and 60 total MOA internal adjustment. The Mil version has 0.1 MilRad clicks with 17 total MRAD internal adjustment travel. On both versions, a side-mounted control offer 10 intensity levels of red illumination.

5. CDNN Holster Sale — Huge Savings — Everything Under $20.00

CDNN Holster deal bargain sale

Currently, CDNN is running a great Holster Liquidation Sale. Every holster in stock is just $19.99, including some models that normally retail for over $85.00. Chose from quality polymer holsters or traditional leather holsters from Mitch Rosen. Many of these holsters are designed for Sig Sauer pistols, but there are holsters for other popular pistol brands as well.

6. Amazon — Plano 52″ Double Rifle Case with Wheels, $109.08

Plano double scoped rifle case with wheels

This Plano Double Scoped Rifle Case is an Amazon Best Seller for good reason. It offers the functionality and durability of an SKB-type hard case for HALF the money. This is under $110.00, while the equivalent SKB is around $240.00, so you can buy two Planos for the price of one SKB. The 51.5″ interior will fit most scoped competition rifles up to about 29″ barrels (measure your own rifle to make sure). If you separate the barreled action from the stock you can transport even ultra-long ELR rifles. The handles are convenient and beefy and the wheels make this case easy to move. This is a very tough, roomy case for the money (plus there’s Free Shipping).

7. Midsouth — Hornady LnL Auto Charge Scale/Dispenser, $158.99

Hornady Lock and load auto charge scale powder dispenser sale discount

The Hornady Lock N Load Auto Charge Electronic Scale/Dispenser is now on sale for just $158.99 at Midsouth Shooters Supply, discounted way down from the regular $226.24 price. That’s the lowest price we’ve seen on this product in a long time, making this a real bargain. If you are looking for an affordable combination digital scale and powder dispenser, this is very attractive pricing. By comparison, the new RCBS ChargeMaster Lite sells for around $250.00 and is back-ordered at most vendors. That means you can save at least $90.00 by buying RED instead of GREEN.

8. Amazon — Neiko Digital Calipers, $16.85

Amazon Neiko Digital Caliper

Even if you have a good set of calipers, you may want to get one of these Neiko 01407A Digital Calipers. The #1 best-selling digital caliper on Amazon.com, this Neiko tool features a large LCD Screen and measures up to 6.0 inches. With over 3000 customer reviews, this product has earned an overall rating of 4.4 out of 5 stars. It’s hard to go wrong for $16.85, even if you just use these as a spare set for measuring group sizes and case trim lengths.

Permalink Bullets, Brass, Ammo, Hot Deals, Optics 1 Comment »
August 19th, 2018

Hodgdon Reloading Data Center — Good Place to Start

Hodgdon Reloading data Center hand loading powder

Hodgdon Reloading data Center hand loading powderLooking for a good load for a new rifle? Or perhaps you want to try a new powder and bullet combo for an existing rig. One of the best places to start for load data is Hodgdon’s online Reloading Data Center for pistol, rifle, and shotgun reloaders. Check out the enhanced Data Center at www.HodgdonReloading.com.

In the Data Center, you’ll find thousands of load recipes for pistol, rifle, and shotgun. Rifle shooters will find dozens of loads for their favorite Hodgdon, IMR, and Winchester powders such as H4198, Varget, H4350, and IMR 8208 XBR. And Hodgdon’s Reloading Center is “mobile-friendly” so it works well with smartphones and tables. Navigation is easy, and you can set the search criteria easily choosing your favorite powder or bullets. After choosing a cartridge, you can pre-select specific bullet weights and powder types. That quickly delivers just the information you want and need. You won’t have to scroll through scores of entries for bullets or powders you don’t use.

Hodgdon Reloading data Center hand loading powder

Mobile users will notice that the updated/enhanced Reloading Center is much more “user-friendly” for smart-phone and tablet users. Controls have been optimized for touch-screens, and buttons are large and easy to use. Likewise the results are displayed in a large, easy-to read format.

Hodgdon tip from EdLongrange. We welcome reader submissions.
Permalink Reloading, Tech Tip No Comments »
July 20th, 2018

Try Rotating Cases During Bullet Seating to Reduce Run-Out

Bullet Seating Reloading rotate cartridge Run-out TIR

Here is a simple technique that can potentially help you load straighter ammo, with less run-out (as measured on the bullet). This procedure costs nothing and adds only a few seconds to the time needed to load a cartridge. Next time you’re loading ammo with a threaded (screw-in) seating die, try seating the bullet in two stages. Run the cartridge up in the seating die just enough to seat the bullet half way. Then lower the cartridge and rotate it 180° in the shell-holder. Now raise the cartridge up into the die again and finish seating the bullet.

Steve, aka “Short Range”, one of our Forum members, recently inquired about run-out apparently caused by his bullet-seating process. Steve’s 30BR cases were coming out of his neck-sizer with good concentricity, but the run-out nearly doubled after he seated the bullets. At the suggestion of other Forum members, Steve tried the process of rotating his cartridge while seating his bullet. Steve then measured run-out on his loaded rounds. To his surprise there was a noticeable reduction in run-out on the cases which had been rotated during seating. Steve explains: “For the rounds that I loaded yesterday, I seated the bullet half-way, and turned the round 180 degrees, and finished seating the bullet. That reduced the bullet runout by almost half on most rounds compared to the measurements from the first test.”

READ Bullet Seating Forum Thread »

run-out bullet

run-out bullet

Steve recorded run-out measurements on his 30BR brass using both the conventional (one-pass) seating procedure, as well as the two-stage (with 180° rotation) method. Steve’s measurements are collected in the two charts above. As you can see, the run-out was less for the rounds which were rotated during seating. Note, the change is pretty small (less than .001″ on average), but every little bit helps in the accuracy game. If you use a threaded (screw-in) seating die, you might try this two-stage bullet-seating method. Rotating your case in the middle of the seating process won’t cost you a penny, and it just might produce straighter ammo (nothing is guaranteed). If you do NOT see any improvement on the target, you can always go back to seating your bullets in one pass. READ Forum Thread..

Permalink Bullets, Brass, Ammo, Reloading 5 Comments »
July 15th, 2018

How Ammo Temp Affects Pressure, Velocity, and Point of Impact

Sierra Bullets Ammunition Ammo temperature temp test hot F-Class Ammo cold
In this .308 Win test, 70° F ammo shot 96 FPS slower than ammo heated to 130.5° F. And the 130.5° ammo was 145 fps faster than ammo right out of the freezer (at 25.5° F). That’s a huge difference…

EDITOR’s NOTE: The Sierra tester does not reveal the brand of powder tested here. Some powders are much more temp sensitive than others. Accordingly, you cannot extrapolate test results from one propellant to another. Nonetheless, it is interesting to see the actual recorded velocity shift with ammo temperature variations in a .308 Win.

Written by Sierra Chief Ballistician Tommy Todd
This story originally appeared in the Sierra Bullets Blog
A few weeks ago I was attending the Missouri State F-Class Match. This was a two-day event during the summer and temperatures were hot one day and hotter the next. I shot next to a gentleman who was relatively new to the sport. He was shooting a basically factory rifle and was enjoying himself with the exception that his scores were not as good as he hoped they would be and he was experiencing pressure issues with his ammunition. I noticed that he was having to force the bolt open on a couple of rounds. During a break, I visited with him and offered a couple of suggestions which helped his situation somewhat and he was able to finish the match without major issues.

He was shooting factory ammunition, which is normally loaded to upper levels of allowable pressures. While this ammunition showed no problems during “normal” testing, it was definitely showing issues during a 20-round string of fire in the temperatures we were competing in. My first suggestion was that he keep his ammunition out of the direct sun and shade it as much as possible. My second suggestion was to not close the bolt on a cartridge until he was ready to fire. He had his ammo in the direct sunlight and was chambering a round while waiting on the target to be pulled and scored which can take from a few seconds to almost a minute sometimes.

This time frame allowed the bullet and powder to absorb chamber [heat] and build pressure/velocity above normal conditions. Making my recommended changes lowered the pressures enough for the rifle and cartridge to function normally.

Testing Effects of Ammunition Temperature on Velocity and POI
After thinking about this situation, I decided to perform a test in the Sierra Bullets underground range to see what temperature changes will do to a rifle/cartridge combination. I acquired thirty consecutive .30 caliber 175 grain MatchKing bullets #2275 right off one of our bullet assembly presses and loaded them into .308 Winchester ammunition. I utilized an unnamed powder manufacturer’s product that is appropriate for the .308 Winchester cartridge. This load is not at the maximum for this cartridge, but it gives consistent velocities and accuracy for testing.

I took ten of the cartridges and placed them in a freezer to condition.

Sierra Bullets Ammunition Ammo temperature temp test hot F-Class Ammo cold

Sierra Bullets Ammunition Ammo temperature temp test hot F-Class Ammo cold

I set ten of them on my loading bench, and since it was cool and cloudy the day I performed this test I utilized a floodlight and stand to simulate ammunition being heated in the sun.

Sierra Bullets Ammunition Ammo temperature temp test hot F-Class Ammo cold

I kept track of the temperatures of the three ammunition samples with a non-contact laser thermometer.

The rifle was fired at room temperature (70 degrees) with all three sets of ammunition. I fired this test at 200 yards out of a return-to-battery machine rest. The aiming point was a leveled line drawn on a sheet of paper. I fired one group with the scope aimed at the line and then moved the aiming point across the paper from left to right for the subsequent groups.

NOTE that the velocity increased as the temperature of the ammunition did.

The ammunition from the freezer shot at 2451 fps.

Frozen FPS

The room temperature ammunition shot at 2500 fps.

Room Temperature FPS

The heated ammunition shot at 2596 fps.

Sierra Bullets Ammunition Ammo temperature temp test hot cold

The tune window of the particular rifle is fairly wide as is shown by the accuracy of the three pressure/velocity levels and good accuracy was achieved across the board. However, notice the point of impact shift with the third group? There is enough shift at 200 yards to cause a miss if you were shooting a target or animal at longer ranges. While the pressure and velocities changed this load was far enough from maximum that perceived over pressure issues such as flattened primer, ejector marks on the case head, or sticky extraction did not appear. If you load to maximum and then subject your ammunition to this test your results will probably be magnified in comparison.

Sierra Bullets Ammunition Ammo temperature temp test hot cold

This test showed that pressures, velocities, and point-of-impact can be affected by temperatures of your ammunition at the time of firing. It’s really not a bad idea to test in the conditions that you plan on utilizing the ammo/firearm in if at all possible. It wouldn’t be a bad idea to also test to see what condition changes do to your particular gun and ammunition combination so that you can make allowances as needed. Any personal testing along these lines should be done with caution as some powder and cartridge combination could become unsafe with relatively small changes in conditions.

Permalink Bullets, Brass, Ammo, Reloading, Tech Tip 2 Comments »
July 6th, 2018

TECH Tip: Safe Loading Practices for Different Bullet Shapes

USAMU Reloading Bullet Safety

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.

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.

Photo 1: Three Near-Equal-Weight 7mm Bullets with Different Shapes
USAMU Bullet Ogive Comparison Safety Reloading

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.

Bullet 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.

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.

Permalink Reloading, Tech Tip 1 Comment »
June 22nd, 2018

How to Improve Case Concentricity with Standard Seating Dies

USAMU Handloading Hump Day Seating Die Adjustment Stem TIR Concentricity Run-out

Each Wednesday, the U.S. Army Marksmanship Unit publishes a reloading “how-to” article on the USAMU Facebook page. This USAMU “Handloading Hump Day” article, the second in a series on improving concentricity, has many useful tips. If you use standard (non-micrometer) seating dies when loading some cartridge types, this article is worth reading. And visit the USAMU Facebook page next Wednesday for the next installment.

Once again, it’s time for USAMU’s “Handloading Hump-Day!” Last week, we addressed achieving very good loaded-cartridge concentricity (AKA “TIR”, or Total Indicator Runout) using standard, “hunting grade” reloading dies.

We explained how to set up the Full-Length Size die to float slightly when correctly adjusted for desired case headspace. We also cited a study in which this method loaded ammunition straighter than a set of [higher grade] match dies from the same maker. [One of the keys to reducing TIR with both sets of dies was using a rubber O-ring below the locking ring to allow the die to float slightly. READ Full-Length Sizing Die TIP HERE.]

Now, we’ll set up a standard seating die to minimize TIR — the other half of the two-die equation. As before, we’ll use a single-stage press since most new handloaders will have one. A high-quality runout gauge is essential for obtaining consistent, accurate results.

Having sized, primed and charged our brass, the next step is bullet seating. Many approaches are possible; one that works well follows. When setting up a standard seating die, insert a sized, trimmed case into the shell-holder and fully raise the press ram. Next, back the seating stem out and screw the die down until the internal crimping shoulder touches the case mouth.

Back the die out one-quarter turn from this setting to prevent cartridge crimping. Next, lower the press ram and remove the case. Place a piece of flat steel on the shellholder and carefully raise the ram. Place tension on the die bottom with the flat steel on the shellholder. This helps center the die in the press threads. Check this by gently moving the die until it is well-centered. Keeping light tension on the die via the press ram, secure the die lock ring.

USAMU Handloading Hump Day Seating Die Adjustment Stem TIR Concentricity Run-out

If one were using a micrometer-type seating die, the next step would be simple: run a charged case with bullet on top into the die and screw the seating stem down to obtain correct cartridge OAL.

However, with standard dies, an additional step can be helpful. When the die has a loosely-threaded seating stem, set the correct seating depth but don’t tighten the stem’s lock nut. Leave a loaded cartridge fully raised into the die to center the seating stem. Then, secure the stem’s lock nut. Next, load sample cartridges and check them to verify good concentricity.

One can also experiment with variations such as letting the seating stem float slightly in the die to self-center, while keeping correct OAL. The runout gauge will show any effects of changes upon concentricity. However, the first method has produced excellent, practical results as evidenced by the experiment cited previously. These results (TIR Study 2) will reproduced below for the reader’s convenience.

TIR Study 2: Standard vs. Match Seating Dies

50 rds of .308 Match Ammo loaded using carefully-adjusted standard dies, vs. 50 using expensive “Match” dies from the same maker.

Standard dies, TIR:
0.000” — 0.001” = 52%;
0.001”– 0.002” = 40%;
0.002”– 0.003” = 8%. None greater than 0.003”.

“Match” dies, TIR:
0.000”– 0.001” = 46%;
0.001” — 0.002” = 30%;
0.002” — 0.003” = 20%;
0.003” — 0.004” = 4%.

AccurateShooter Comment: This shows that, with careful adjustment, the cheaper, standard dies achieved results that were as good (or better) than the more expensive “Match” Dies.

These tips are intended to help shooters obtain the best results from inexpensive, standard loading dies. Especially when using cases previously fired in a concentric chamber, as was done above, top-quality match dies and brass can easily yield ammo with virtually *no* runout, given careful handloading.

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