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.
User 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[.]”
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.
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 Like 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.
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.
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.
Western Powders has released its NEW Handloading Guide, Edition 7.0. This $2.99 print resource contains the latest load data for Western’s propellants including Accurate, Ramshot, and Blackhorn powders. Edition 7.0 features the most current data available for Ramshot and Accurate powders, including popular LT30 and LT32, and new Accurate TCM, Accurate 11FS and Ramshot LRT propellants. This latest load guide also has load data for the new 224 Valkyrie, 300 Norma, and 30 Nosler cartridges. Along with reloading recipes, this resource features helpful articles on handloading methods and rifle maintenance/cleaning with X-Treme products.
In the new Handloading Guide 7.0 , you’ll find load data for over 100 rifle cartridges. The cartridge listings are up to date — you’ll find the popular new mid-sized competition cartridges, such as the 6.5 Creedmoor and 6.5×47 Lapua, along with many popular wildcat varmint cartridges, such as the 20 Vartarg, 20 Tactical, and 20 BR. Benchresters will also find recipes for the new LT 30 and LT 32 powders which have proven very accurate in the 30BR and 6PPC respectively.
Download FREE Version 6.0 Guide:
If you can live without the very latest info, you can still get Version 6.0 of Western’s Reloading Guide for FREE. That’s right Version 6.0 is a FREE downloadable PDF. This FREE Reloading & Load Data Guide (Edition 6.0) contains thousands of recipes for handgun and rifle cartridges (plus shotshell and muzzle-loading info).
Do You Like H4350? Then You Should Try Reloder 16 — It Is Accurate and Temp Stable
Alliant Reloder 16 is used now by many top shooters for cartridges that work well with Hodgdon H4350. In fact, we’d say that Reloder 16 is the best substitute for H4350 on the market. Alliant’s RL 16 is very temp stable, offers good velocity, and the accuracy is top tier. Some guys report slightly better accuracy than H4350 in the .284 Win, .260 Rem, 6.5 Creedmoor, 6mm Creedmoor, and 6XC cartridges. If you currently use H4350, you should definitely give Alliant Reloder 16 a try. The powder also boasts excellent lot-to-lot consistency and contains a proprietary de-coppering additive.
This is NOT just a slower version of Alliant’s double-based Reloder 15 (which words great in the 6mmBR and Dasher cartridges). Reloder 16 is a completely new formulation, produced in Sweden by Bofors for Alliant. Reloder 16 utilizes TZ technology, which manipulates the response of the propellant and resists the natural tendency to generate more pressure at higher temperatures and less pressure at lower temperatures. As a result, Alliant’s Reloder 16 offers truly outstanding temperature stability.
Match and Hunting Cartridge Applications:
Alliant tells us that Reloder 16 “is ideal for traditional hunting cartridges, such as .30-06 Springfield and .270 Winchester, as well as 6.5mm target loads and tactical applications wherein temperature stability is required.” We also think the powder will work well in these popular match cartridges: 6XC, 6mm Creedmoor, .243 Win, 6.5×47 Lapua, 6.5 Creedmoor, .260 Rem, .284 Win, and .300 WSM. For example, Alliant’s Reloder 16 Load Data Page shows a 2932 FPS load with Berger 130 grain Hybrid bullet in the 6.5 Creedmoor.
Alliant Reloder 16 Load DATA for 6.5 Creedmoor:
Alliant Reloder 16 Load DATA for .243 Winchester:
NOTE: This is a partial .243 Win Data set. More loads available HERE.
What kind of 200-yard accuracy can you get in an enclosed, underground test range? Would you believe 0.162 MOA at 200 yards with a .338? Have a look at these test targets from Sierra Bullets. Like most bullet manufacturers, Sierra does live-fire bullet testing to ensure that Sierra projectiles perform as promised, with repeatable accuracy. Sierra tests bullets in its own underground test complex. Sierra’s 300-meter test range is the longest, privately-owned underground bullet test facility in the Western Hemisphere. (RWS has a 500m test tunnel in Germany). Sierra offers free tours of the test tunnel as part of Sierra’s Factory Tour Program.
Day in and day out, various bullet types are tested using a big collection of barreled actions. These barreled actions are clamped in stout, return-to-battery test fixtures. These big, heavy test fixtures provide near-perfect repeatability (with no human-induced holding or aiming errors).
Sierra Bullets 10-Shot Groups at 200 yards
Check out these 10-shot test groups shot at the Sierra Test Range at 200 yards. Note that the numbers listed on each sample are actual measurements in inches. To convert to MOA, cut those numbers in half (to be more precise, divide by 2.094, which is 1 MOA at 200 yards). For example, the 0.340″ middle group works out to 0.162 MOA at 200 yards.
Scan-Verified 0.162 MOA Accuracy at 200 Yards
To verify the accuracy of Sierra’s measurements, we measured the middle (.338 caliber) 10-shot group with our On-Target Group Measurement software. We registered a group size reading of 0.339″ — within one-thousandth of the Sierra measurement*. The calculated group size in MOA (Minute of Angle) is 0.162. That’s amazingly good for ten rounds of big .338 caliber bullets. A FIVE-shot 0.162 MOA group at 200 would be considered excellent at any benchrest match. But remember this target has TEN shots. The current, one-target IBS world record for ten shots at 200 yards is 0.245″, set by Ed Watson in 1999.
Bevy of Barreled Actions for Bullet Testing
Sierra Bullets uses dozens of barreled actions for testing bullets in its enclosed, 200-yard test range. Each barrel has its own logbook to track the barrel’s usage.
Click Photo to Zoom
*Note, there were ten (10) shots in the group, but for simplicity we are only displaying five (5) shot circles. Adding more circles won’t change the measurement because the two most distant shots, which determine group size, ARE included.
Do you need to pull bullets that have been seated in a case? You can use lever-actuated, collet-type pullers, or inertial hammer-style pullers, but there is a faster solution. The Grip-N-Pull bullet puller is a precision-machined hand clamp that works for multiple calibers. A single Grip-N-Pull can replace several other tools, while being faster to use. With larger-diameter bullets loaded with light-to-moderate neck tension, it works well. The bullets come out pretty easily, with no scuff marks or dents. For smaller-diameter, .204 to .243 caliber bullets, it may be hard to grip the bullet easily, or you may end up with some jacket damage. And we wouldn’t use this for factory-crimped cartridges.
Introduction to Grip-N-Pull — How It Works:
How to Use the Grip-N-Pull
Put your loaded case in the shell-holder on a reloading press. Raise the ram so the bullet is exposed at the top of the press. Then select the correct, caliber-specific slot in the Grip-N–Pull, clasp the bullet firmly, then lower the ram. The bullet withdraws from the case-neck, retained in the tool. Fast and simple. If there isn’t much neck tension (or a crimp), the bullet should come out undamaged.
Not So Great for Small-Diameter Bullets
Watch this video — the tester says the Grip-N-Pull works well with larger-diameter bullets, but there can be slippage with smaller-diameter projectiles, or those with short bearing surfaces. NOTE: When there is a lot of neck tension, you have to grip extremely hard which can cause your hand to hurt after a while. And the bullets can get marred.
This video explains some of the shortcomings of the Grip-N-Pull.
Four Grip-N-Pull Models Available Grip-N-Pull bullet pullers can be used for multiple calibers. For example, the Standard Rifle Grip-N-Pull pulls bullets for these calibers: .17, .20, .22, .24, .25, .26, .27, .28, and .30. The Large Rifle model works with 8mm, .338, .375, .416 and .458. There is a third model for pistol cartridges, and a fourth “Mil-Spec” unit that does 5.56, 7.62, .338 and .50 BMG. Grip-N-Pull bullet pullers are made of 1/4″ heavy-duty #30 stainless steel and are backed by a lifetime warranty.
Speed and Efficiency of Grip-N-Pull
The Grip-N-Pull’s creators claim this hand clamp cuts bullet pulling time in half. For a speed comparison between Grip-N-Pull and a hammer-style (inertial) bullet puller, watch this Extreme Outer Limits video. Bob and Chris Beck do a head-to-head comparison between the Grip-N-Pull and an inertia puller. It’s no contest — the Grip-N-Pull is way faster, and the powder stays in the case.
Pull Comparison — Grip-N-Pull Vs. Hammer-Style Inertial Puller
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 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.
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. Palmetto Armory — Rem 700 .223 Rem with Scope, $359.99
Here’s an awesome deal on a camo-finish Remington 700 hunting/varminting rig. The price is just $359.99 with scope and rings! This Rem 700 features 26” blued heavy barrel chambered in .223 Rem, Mossy Oak Camo synthetic stock, and X-Mark Pro (non-adjustable) trigger. The package comes complete with a 4-12x40mm scope. NOTE: The twist is 1:12″ so this is suitable for lighter-weight bullets. Buyers say the scope is pretty cheap, though functional. But this is still a great deal. You could pay as much (or more) just for a Rem 700 short action with trigger. Here you get a complete rifle with a pretty nice hunting stock. Order HERE.
2. Grafs.com — 10% OFF All Powders and Primers
Grafs.com is running a great reloading special right now, offering 10% OFF all powder and primers through October 3, 2018. Virtually all your favorite propellants are on sale — Accurate, Alliant, Hodgdon, IMR, Norma, Ramshot, Vectan, Vihtavuori, Winchester and more. In addition, you can save 10% on primers from CCI, Federal, Winchester and other leading brands. Shipping and HazMat fees still apply. Along with these specials, Grafs.com is offering 10% Off Peterson Brass (no listed end date on Peterson brass discount). Hats off to EdLongRange for finding these Graf’s deals.
Here’s a killer deal on a Front Focal Plane (FFP) optic good for PRS competition and tactical applications. The Vortex Viper PST 6-24x50mm scope features 0.1 Milrad clicks with an EBR-2C illuminated reticle with Mil-based hash marks. This reticle also features the “Christmas Tree” type lower half, which provides range hold-overs with horizontal markings for wind holds. Not that long ago, this scope sold for around a thousand bucks. Now you can get the Vortex Viper PST 6-24x50mm for just $649.99. That’s a great price for a PRS-ready FFP comp scope with a proven track record and rock-solid Vortex warranty. EuroOptic’s Sale price is $649.99. This is a great deal — this same scope sells elsewhere for $789.99.
4. Precision Reloading — 15% Off All Battenfeld Brand Products
Visit PrecisionReloading.com to save big on Caldwell Rests and Target Cams, Tipton Cleaning Rods and Gun Vises, Frankford Arsenal Tumbler Kits, Golden Rod Dehumidifiers, and Wheeler Engineering Reloading Tools. We use a Tipton Gun Vise, and clean brass with a Frankford Arsenal Tumbler and media separator. We also think the Caldwell Target Cam is one of the best values on the market. It out-performs long range video systems costing hundreds more. HEADS UP: While you’re shopping at PrecisionReloading.com, note that the HazMat fee is only $16 for any powder and/or primer order. That’s half what some other vendors charge.
5. CDNN — Ruger EC9S Carry Pistol, $229.99
Here’s a good little 9mm carry pistol for a crazy-low price. Right now, CDNN is selling the popular Ruger EC9S 9MM pistol for $229.99 — that’s $70 off the regular $299.00 price. This gun is light (17.2 ounces) and thin so it’s easy to carry discretely. The EC9S is 6″ overall with a 3.12″-long barrel. The EC9S features integral sights and ships with a single 7-round magazine.
6. Midsouth — New Lyman Reloading Presses on Sale
Midsouth Shooters Supply is running a big sale right on Lyman’s impressive new Brass Smith line of reloading presses. There are three models, each offering great performance and value for its class. You can save quite a bit of cash with this Midsouth Lyman Press sale. If you haven’t tried orange yet, we think you’ll be impressed. The little C-Frame is a steal at $69.99. The sturdy O-Frame Singles stage press is $154.99. And if you’re looking for a Turret press, the new 8-station Lyman Turret press ($192.99 on sale) is very impressive — with more stations than the competition, and enhanced strength/rigidity.
7. Amazon — NcStar Roll-Up Shooting Mat, $29.95
Thicker and bigger than most shooting mats under $60.00, this $29.95 NcStar Roll-Up Mat has earned excellent reviews for comfort and utility. It has 0.30″ padding plus elbow and knee panels. The mat rolls up into a compact 19.5″ W x 8.5″ H, secured by twin Velcro straps The mat is available in six colors: Tan (shown), green, black, camo, digital camo, and grey. Prices vary slightly among colors. With both carry handle AND shoulder strap, the rolled mat is easy to tote. Here are reviews from three recent verified purchasers:
“This mat is fantastic, the stitching is solid, the padding is thick enough that rocks and cactus aren’t a problem. It’s light, quick, and easy to roll up.” — Angela D.
“Excellent mat. Used it for a Project Appleseed shoot and it performed perfectly. Two days of kneeling, standing and laying on it, over a dirty, dusty shooting range. Came through it all with flying colors. Rolls nicely [and] well-constructed from high-quality materials.” — NPCoach
“Works better than I expected. Easy to roll up and unroll in seconds. Velcro ties save a lot of time. It’s not uncomfortable laying on hard, uneven ground. Great product!” — Robert
8. Midsouth — 17 HMR Ammo Sale, $33.79 for 200 Rounds
Every good varmint hunter has a 17-cal rimfire in his arsenel. The 17 HMR is ideal for small critters out to about 150 yards. Low noise and low recoil help you score multiple hits. Now’s a great time to stock up on 17 HMR ammunition. Midsouth has Hornady 17 HMR in 200-count packs for $33.79. That works out to $8.45 per 50-count box or $0.17 (seventeen cents) per round. This is good ammo — the tipped V-Max bullets are explosive on ground squirrels and prairie dogs. NOTE: Midsouth also has 500-round 17 HMR bricks for $84.99, also $0.17 per round.
9. Midsouth — 250 Adhesive Precision Targets on Roll, $12.49
Midsouth offers 250 self-adhesive Benchrest Targets on a convenient roll. These stick-on targets work great for load development. The aiming diamond helps align the cross hairs of your scope for consistent shot placement. If you set your Point of Impact to the 1/4″ grid pattern at the top it’s easy to eyeball your group size. At the bottom are fields for your load info. Each Target sticker measures 6″ x 4″ with a 4.5″ x 2.5″ printed area. Midsouth sells the 250-target roll for $12.49, discounted this week from $14.99.
What is “Overbore”? That’s a question rifle shooters can debate to no end. This article from our archives proposes one way to identify “overbore cartridges”. We think the approach outlined here is quite useful, but we know that there are other ways to define cartridges with “overbore” properties. Whenever we run this article, it stimulates a healthy debate among our readers — and that is probably a good thing.
Forum Member John L. has been intrigued by the question of “overbore” cartridges. People generally agree that overbore designs can be “barrel burners”, but is there a way to predict barrel life based on how radically a case is “overbore”? John notes that there is no generally accepted definition of “overbore”. Based on analyses of a wide variety of cartridges, John hoped to create a comparative index to determine whether a cartridge is more or less “overbore”. This, in turn, might help us predict barrel life and maybe even predict the cartridge’s accuracy potential.
John tells us: “I have read countless discussions about overbore cartridges for years. There seemed to be some widely accepted, general rules of thumb as to what makes a case ‘overbore’. In the simplest terms, a very big case pushing a relatively small diameter bullet is acknowledged as the classic overbore design. But it’s not just large powder capacity that creates an overbore situation — it is the relationship between powder capacity and barrel bore diameter. Looking at those two factors, we can express the ‘Overbore Index’ as a mathematical formula — the case capacity in grains of water divided by the area (in square inches) of the bore cross-section. This gives us an Index which lets us compare various cartridge designs.”
OVERBORE INDEX Chart
So what do these numbers mean? John says: “My own conclusion from much reading and analysis is that cartridges with case volume to bore area ratio less than 900 are most likely easy on barrels and those greater than 1000 are hard on barrels.” John acknowledges, however, that these numbers are just for comparison purposes. One can’t simply use the Index number, by itself, to predict barrel life. For example, one cannot conclude that a 600 Index number cartridge will necessarily give twice the barrel life of a 1200 Index cartridge. However, John says, a lower index number “seems to be a good predictor of barrel life”.
John’s system, while not perfect, does give us a benchmark to compare various cartridge designs. If, for example, you’re trying to decide between a 6.5-284 and a 260 Remington, it makes sense to compare the “Overbore Index” number for both cartridges. Then, of course, you have to consider other factors such as powder type, pressure, velocity, bullet weight, and barrel hardness.
Overbore Cases and Accuracy
Barrel life may not be the only thing predicted by the ratio of powder capacity to bore cross-section area. John thinks that if we look at our most accurate cartridges, such as the 6 PPC, and 30 BR, there’s some indication that lower Index numbers are associated with greater inherent accuracy. This is only a theory. John notes: “While I do not have the facilities to validate the hypothesis that the case capacity to bore area ratio is a good predictor of accuracy — along with other well-known factors — it seems to be one important factor.”
User Review by Tommy Todd
Like 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.
Scan-Verified 0.162 MOA Accuracy at 200 Yards
