Over the years, the U.S. Army Marksmanship Unit (USAMU) published a series of reloading articles on its Facebook Page. In this article, the second in a 3-part series, the USAMU covers the process of loading competition pistol ammunition. The authors focus on two key elements — the taper crimp and the quality/uniformity of the original brass. If you shoot pistol competitively, or just want to maximize the accuracy of your handguns, read this article. The taper crimp tips are very important.
Loading Accurate Competition Pistol Ammunition — Part 2 of 3
One often-overlooked aspect of handloading highly-accurate pistol ammunition is the amount of taper crimp used, and its effect on accuracy. (NOTE: this article pertains to loading for semi-autos — revolver crimp techniques involve some quite different issues.) Briefly, different amounts of taper crimp are used with various handloads to obtain best accuracy. The amount is based on bullet weight, powder burn rate and charge, plus other factors such as case neck tension. During machine-rest testing of experimental Service Pistol ammunition, many variables are examined. Among these, our Shop often varies a load’s crimp in degrees of 0.001″ when re-testing for finest accuracy.
How to Measure Taper Crimp on Pistol Cartridges
One question that often arises is, “How do I measure the taper crimp I’m putting on my cartridges?” Using the narrow part of one’s dial caliper jaws, carefully measure the case diameter at the exact edge of the case mouth on a loaded cartridge. It’s important to take several measurements to ensure consistency. Also, be sure to measure at several places around the case mouth, as case wall thickness can vary. After measuring 2-3 cartridges with a given crimp setting, one can be confident of the true dimension and that it can be repeated later, if needed.
However, for good results, one must use brass from one maker due to variances in case wall thickness. For example, the same degree of crimp that imparts a measurement of 0.471″ with Brand X brass may result in 0.469″ with Brand Y. Thus, for best accuracy, using brass from the same manufacturer is important — particularly for 50-yard Slow Fire. In a perfect world, it is better still to use brass from one lot number if possible. With the popularity of progressive presses using interchangeable tool heads, keeping separate tool heads adjusted for each load helps maximize uniformity between ammunition lots.
Brass Uniformity and Accuracy
Brass is important to pistol accuracy. While accurate ammunition can be loaded using brass of mixed parentage, that is not conducive to finest results, particularly at 50 yards. It is important for the serious competitor to pay attention to his brass – even if only for the 50-yard “Slow Fire” portions of “Bullseye” matches and practice. By segregating brass as described above, and additionally keeping track of the number of times a given batch of cases has been fired, one can ensure case neck tension and case length are at their most uniform.
Given the large volumes of ammunition consumed by active pistol competitors, using inexpensive, mixed surplus brass for practice, particularly at the “short line” (25 yards), is understandable. In NRA Outdoor Pistol (“Bullseye”), the 10-ring is relatively generous — especially for a well-trained shooter with an accurate pistol and load. However, for the “long line” (50 yards), purchasing and segregating a lot of high-quality brass to be used strictly for slow-fire is a wise idea. To keep track of your brass on the line, use a unique headstamp marking with 1 or 2 colors of marking pen ink.
Uniform Cartridge Overall Length is Important
Cartridge case Overall Length (OAL) uniformity as it comes from the factory is important to achieving utmost accuracy. More uniform case lengths (best measured after sizing) contribute to greater consistency of crimp, neck tension, ignition/burn of powder charge, headspace (rimless cartridges), etc. Cartridge case-length consistency varies noticeably by maker and, with lesser manufacturers, also from lot to lot. Some manufacturers are more consistent in their dimensions than others, and also in the hardness/ductility of their brass. Similarly, pay attention to primer brands, powder lot numbers, etc.
Consider Using a Lock-Out Die with Progressive Presses
When reloading pistol ammo with a Progressive press, we strongly recommend the use of a lock-out die, or other system that can detect double charges or low charges. If your progressive is manually advanced, the possibility of a double charge is very real — and that can have disastrous consequences.
On UltimateReloader.com website you’ll find an excellent two-part series on the function and set-up of the RCBS Lock-Out Die. This die prevents loading if a high or low powder charge is detected. The video below shows setup of the RCBS Lock-Out Die on the Dillon XL-650 progressive press.
Sinclair International has created a series of instructional videos illustrating the basics of metallic cartridge reloading. The 8-Part series starts with reloading basics and provides step-by-step, how-to instructions that will help new reloaders get started. Detailed, animated illustrations show you what happens inside the chamber when shooting, and inside the dies during each step of reloading. The videos can be viewed on Sinclair International’s YouTube channel. Shown below is the first video in the series:
Each of the Sinclair videos is hosted by then Sinclair Int’l President Bill Gravatt (now with Creedmoor Sports). Bill doesn’t just show you “how”, he tells you “why”. The how-to segments cover case inspection, proper die set up, case sizing, primer installation, powder measuring, bullet seating, crimping, and even goes into the record keeping needed for the handloader. “We wanted to give shooters who haven’t reloaded a look at all the advantages of creating your own ammo and how easy it is to get started,” said Gravatt, “without telling them they had to have any certain brand or type of equipment to do the job.”
The Eight Video Topics Are:
Part 1 — Intro to Video Series
Part 2 — Intro to Reloading Safety
Part 3 — Metallic Cartridge Components
Part 4 — The Firing Sequence
Part 5 — Tools for Reloading
Part 6 — Loading Bottle-Neck Cartridges (2 videos)
Part 7 — Loading Straight Wall Cartridges
Part 8 — Reloading Series Conclusion
Reloading Tools
Shown below is Part 5 of the video series, covering the tools used for precision reloading.
We also strongly recommend the Part 4 Video to readers who are getting started in reloading. This “How Things Work” segment covers the sequence of events inside the chamber (and barrel) when the cartridge is fired. The video includes helpful graphics that show what happens to the primer, powder, cartridge, and bullet when the round is fired. The video also illustrates “headspace” and explains how this can change after firing. We think this video answers many common questions and will help reloaders understand the forces at work on their brass during the firing process.
Apparently reducing static charges on and around electronic scales can reduce their propensity to drift, lessening the problem of “wandering zero”. Just how and why static charges interfere with scale performance is unclear, but many shooters have noticed that static electricity can cause electronic scales to behave strangely. So how do you reduce static charges around your digital balance? Our late friend German Salazar (aka “GS Arizona”), creator of the Rifleman’s Journal Blog, found a very simple solution — an anti-static aerosol spray — that, by all indications, actually works. When this “spray-can solution” was suggested to German by a fellow shooter, German was skeptical. However, he tried the stuff and he says that it really does help the scale maintain zero over time, with much less observed drift.
Static Guard Reduced Scale Drift
German Salazar explained that the use of “Static Guard” spray helped mitigate the problem of a drifting zero on his Ohaus Navigator electronic scale. He writes: “My electronic scale… suffers from drifting zero (as they all seem to). I’ve read dozens of forum posts about drift and how to minimize its occurrence, so I know this problem isn’t limited to my scale or my workshop. Sometime last year, John Lowther mentioned the use of anti-static spray as a solution to the drift problem. John stated that the spray had virtually eliminated drift for him.”
Salazar found that the Static Guard actually worked: “The spray works great, just as John said it would. I spray all surfaces that I touch with my hands and arms as well as the pan (top and bottom), the metal tray on which the pan rests and the table under the scale. In six months or so of using the spray I’ve re-applied it about two or three times; it certainly isn’t something that you need to do each time you sit down to load. Before using the spray, it was not uncommon for me to re-zero the scale 10 times in the course of loading 72 rounds; now it might need it once during a session.”
When developing loads, it is important to know the true internal capacity of your cases, both fired and “as FL-sized”. In particular, when using the QuickLOAD program, it is vital to determine true case capacity. The default case capacity values listed by QuickLOAD may be off half a grain (or more) because brass from different manufacturers can vary considerably in capacity. Case capacity is a very important variable that will affect the pressure of a load and the velocity of your bullets.
To determine the true internal capacity of your cases, first weigh an empty cartridge case, then fill the case with water (all the way to the top of the neck) and weigh the case again. The difference in weight is your H20 capacity in grains. But how do you keep the H20 from flowing out the bottom? When measuring fired, unsized cases, you can simply leave the spent primer in the pocket. However, if you want to measure new brass or “as-FL sized” cases that have been deprimed, you’d have to insert a spent primer to “stem the tide”. Until now that is… 21st Century Shooting sells a great little $5.50 tool that plugs the bottom of the case so you can measure H20 capacity with ease.
When we saw 21st Century’s Primer Pocket Plug we thought “That’s smart — why didn’t someone think about that a long time ago?”. This handy “end-cap” lets you quickly measure multiple new brass cases or deprimed FL-sized cases so you can get an average H20 capacity. The primer pocket plugs are NOT case-specific (they feature an O-ring that fits the pocket). One version will work with all small-primer-pocket cases, while another works with all large-primer-pocket cartridge types. Price is $11.99 for either small-pocket or large-pocket version.
ALTERNATIVE: >If you want to measure H20 capacity on fired, sized brass, but don’t want to shell out the money for the tool (or re-insert a spent primer), here’s a simple suggestion. When you size your case, first remove the decapping rod from the die. Then you can FL-size the case without removing the primer. Of course, you will eventually have to knock the primer out, and that requires putting the decapping rod back in the die and running the case through a second time. To avoid that hassle, the Primer Pocket Plug may be worth the $5.50 over the long haul.
Product Find by ELR Reseacher. We welcome reader submissions.
by Sierra Bullets Ballistic Technician Paul Box
One thing that plays a major role in building an accuracy load is neck tension. I think a lot of reloaders pretty much take this for granted and don’t give that enough thought.
So, how much neck tension is enough?
Thru the years and shooting both a wide variety of calibers and burn rates of powder, I’ve had the best accuracy overall with .002″ of neck tension. Naturally you will run into a rifle now and then that will do its best with something different like .001″ or even .003″, but .002″ has worked very well for me. So how do we control the neck tension? Let’s take a look at that.
First of all, if you’re running a standard sizing die with an expander ball, just pull your decapping rod assembly out of your die and measure the expander ball. What I prefer is to have an expander ball that [can give] you .002″ in neck tension [meaning the inside neck diameter is about .002″ smaller than the bullet diameter after passing the expander through]. If you want to take the expander ball down in diameter, just chuck up your decapping rod assembly in a drill and turn it down with some emery cloth. When you have the diameter you need, polish it with three ought or four ought steel wool. This will give it a mirror finish and less drag coming through your case neck after sizing.
Tips for Dies With Interchangeable Neck Bushings
If you’re using a bushing die, I measure across the neck of eight or ten loaded rounds, then take an average on these and go .003″ under that measurement. There are other methods to determine bushing size, but this system has worked well for me.
Proper Annealing Can Deliver More Uniform Neck Tension
Another thing I want to mention is annealing. When brass is the correct softness, it will take a “set” coming out of the sizing die far better than brass that has become to hard. When brass has been work hardened to a point, it will be more springy when it comes out of a sizing die and neck tension will vary. Have you ever noticed how some bullets seated harder than others? That is why.
Paying closer attention to neck tension will give you both better accuracy and more consistent groups.
Do primer types make a significant difference in accuracy or vertical dispersion at long range? The answer is “maybe”. Here’s one anecdotal study that tracked vertical variance among six different primer types. The tester is a good shooter with a very accurate rifle — four of the six 4-shot groups were under 2″ at 500 yards. This test doesn’t settle the question, but does suggest that it may be worth trying a few different primer types with your match ammo.
Here is a very interesting test for the 6 BRA (6mmBR Ackley) cartridge. Forum member James Phillips, a talented long-range benchrest shooter, tested SIX different primer types from three different manufacturers. To help determine vertical dispersion, James set his target out at 500 yards. He then proceeded to shoot 4-shot groups, in order, with each primer type. Velocities were recorded with a chrono. The photo above shows the results. James says: “I’ll retest the best two for accuracy and consistency with 10 shots each”. CLICK HERE for full-screen target photo.
As you can see, ALL the groups are pretty impressive. The smallest groups, 1.253″, was shot with CCI 400 primers. Next best (and very close) was CCI BR4, at 1.275″ for four shots. The “flat line” winner was the Remington 7.5, at upper left. There was almost no vertical. If you are intrigued by this interesting primer test, you can join the discussion in this Primer Test FORUM THREAD.
Primer Brand
Group Size
Velocity
Extreme Spread
Std Deviation
Remington 7.5
1.985″ 4 shot
2955 FPS
8 FPS
4.0 FPS
Federal 205M
2.200″ 4 shot
2951 FPS
11 FPS
4.8 FPS
Sellier Bellot SR
1.673″ 4 shot
2950 FPS
14 FPS
5.9 FPS
CCI 450M
2.341″ 4 shot
2947 FPS
14 FPS
6.6 FPS
CCI 400
1.253″ 4 shot
2950 FPS
3 FPS
1.3 FPS
CCI BR4
1.275″ 4 shot
2949 FPS
15 FPS
6.9 FPS
CARTRIDGE: 6mmBR Ackley, aka 6 BRA. Parent case is 6mmBR Norma. The 6 BRA is fire-formed to create a 40-degree shoulder and less body taper. Capacity is increased, but the neck is longer than a 6mm Dasher. The capacity is enough to get to the 2950+ FPS accuracy node. Some shooters say the 6 BRA is more forgiving than the 6mm Dasher. The 6 BRA is certainly easier to fire-form.
TEST REPORT — Conditions, Shooting Method, Loading Method
Tester James Phillips posted this report in ourShooters’ Forum:
Conditions: The testing was done in the morning over flags. The flags never moved or even twitched. I had as perfect conditions as I could have asked for. It was overcast so no mirage and no wind. There were no other shooters, just me.
Test Procedure: Each shot was precisely shot at my pace and centered the best possible using my Nightforce 15-55X scope. I did not use the round-robin method. Each four-shot group with the same was shot at one time. Then I moved onto the next primer. Everything felt right for each and every shot fired today. Of course I could repeat the test tomorrow and it could be exact opposite of today’s test. We can chase this forever. But [soon] I’m going to test the BR4 and 400 primer… for best accuracy and consistency for 10 shots each.
How Rounds Were Loaded: Each load was weighed to one (1) kernel of powder. So I know that’s as good as I can weigh them. Each bullet seating force was within 1# on my 21st Century hydraulic arbor press.
Previous Initial Load Testing: All groups were shot with 31.1 grains of H4895. During initial load testing I settled in on the Sellier & Bellot primer to finalize everything as it showed more promise over the CCI 450 Magnum I also tried. I was actually surprised to have seen the higher ES and SD from that primer today along with the vertical shown. [Editor: Look carefully — one shot from the CCI 450 is right in the center black diamond, stretching the vertical. By contrast the Rem 7.5 had almost no vertical.]
Velocity and NODE Considerations: I was about 5-6 FPS above what appeared to been my optimum velocity of 2943-2945 FPS, so I’ll test 5 shots of 31.0 and 5 of 31.1 and see what happens from there. I can only assume my velocities where higher due to the higher humidity and of course temps were 5 degrees warmer this morning as well. It wasn’t far off but I noticed it.
The Pew Pew Tactical website has interesting article on rifle and pistol cartridges and bullet types. This contains a large selection of interesting photographs and illustrations. If you load and/or shoot for a wide variety of cartridge types, you’ll find that article well worth reading. It has nearly 50 photographs and more than a dozen short videos. READ FULL Article.
The article also shows all types of pistol bullets, along with a variety of rifle projectiles. It even illustrates multiple types of shotshell cartridges.
The article also explains the basic components of modern cartridges — bullet, case, powder, and primer:
Photo courtesy Ammunitiontogo.com which sells ammo from many leading brands.
Popular Cartridge Types Profiled
The article provides quick summaries of popular ammunition types including 9mm Luger (9x19mm), .357 Magnum, .40 SW, .45 ACP, .223 Rem, and .308 Winchester. The author’s favorite pistol round is the 9mm Luger: “9mm is my personal favorite and if there was a “Goldilocks” round, this would be it. The very first gun I bought was a 9mm. They’re fun at the range. They’re good for defense. It is the standard round for NATO countries and the majority of police forces around the world. It is mild shooting, can vary in weight from 115 to 147 grains, and has varying stopping power based on the type of bullet.”
This Pew-Pew Tactical guide to cartridge types also provides a quick explanation of cartridge ignition — both centerfire and rimfire: “The rimfire’s primer is built into the rim while the centerfire cartridge has the primer in the center. Pro tip — if you can see a circle in the middle…it’s a centerfire cartridge.”
There are two common types of centerfire primers — Boxer and Berdan. This helpful Wikipedia illustration shows how Boxer, Berdan, and rimfire primers ignite the powder in the cartridge:
This centerfire and rimfire ignition animation is by BBODO – Own work, CC BY-SA 3.0 licensed under the Creative Commons Attribution-Share Alike 3.0 license.
by Sierra Bullets Ballistic Technician Philip Mahin for Sierra Bullets Blog
A lot of calls that come into the Sierra Customer Service Center are made by shooters [of retirement age]. Most of the time the shooter used to reload back when they were [younger] and stopped in order to raise a family, pursue a career, or both. Maybe their father or grandfather taught them back in the day and they are looking for an answer to the new whatchamacallit they found on the internet. The point is they are coming back to it because it was fun.
Reloading Can Provide Stress Relief
As a father of three, a husband, a brother, a son and son-in-law, and a friend and neighbor, I get pulled in a lot of directions. In all honesty, reloading and shooting has become a stress relief for me even though I work in the shooting industry.
Sometimes, the shooting gets put on hold for other more important things but there will always be another project or repair to accomplish. There are a lot out there that have found a way to balance the work life, the family life, and the play life. I would like to applaud you on your efforts because it is a hard thing to accomplish.
Remember to take time and relieve that stress. Do something fun, especially if it is shooting that special hand-load you just made.
AccurateShooter Comment — Hand-Loading and the Creative Process
Reloading your own precise ammo can be rewarding in many ways. First it allows you a temporary escape from work pressures, “Honey-Dos”, filing your taxes — whatever. It’s just you and Mr. Rockchucker spending quality time in the loading room. Second, hand-loading is a creative process that engages the mind. During load development, you are like an inventor, selecting a powder charge, choosing the bushing size, experimenting with seating depths, working to perfect your load.
Lastly, the process of hand-loading is rewarding because you are building something start to finish. You begin with components — bullets, brass, and powder, and end up with a finished product that (hopefully) is better than the best factory ammo you could buy. It is enormously satisfying to start with piles of bullets and brass and end up with beautiful hand-loads that can deliver great accuracy.
Whidden Gunworks makes great sizing and seating dies. The Whidden full-length sizing die with neck bushing is very popular because it allows you to “tune” the neck tension by using different bushings, with larger or smaller inside diameters. In this video, John Whidden explains how to choose a the right bushing size for use with your neck-sizing and full-length sizing bushing dies.
For most applications, John suggest starting with the caliper-measured outside diameter of a loaded cartridge (with your choice of bullet), and then SUBTRACT about three thousandths. For example, if your loaded round mics at .333, then you would want to start with a 0.330 neck bushing. John notes, however, that you may want to experiment with bushings, going down a thousandth and up a thousandth. With thin In addition, as your brass ages and the necks harden, you may want to change your bushing size.
Quick Tip: Try Flipping Your Bushings
You may also want to experiment with “flipping” your neck bushings to alternate the side that first contacts the neck of the case. (One side of the bushing is usually marked with the size, while the other side is unmarked.) So try “number side up” as well as “number side down”.
Some folks believe that one side of the bushing may allow a smoother entry, and that this can enhance concentricity. Other people think they can get very slightly more or less neck tension depending on how the bushing is oriented. This is a subtle effect, but it costs nothing to experiment.
If one bushing orientation proves better you can mark the “up” side with nail polish so that you can always orient the bushing optimally. NOTE: We have confirmed that some bushings are actually made with a slight taper. In addition, bushings may get distorted slightly when the brand name and size is stamped. Therefore there IS a reason to try both orientations.
The RCBS Lock-Out Die can also be used with some Dillon and Hornady progressive presses.
If you load pistol or rifle ammo with a progressive press, we strongly recommend you get a Lock-Out Die from RCBS. This unique reloading die will prevent your progressive press from advancing if the dispensed powder charge is more or less than about 0.3 grains too high or too low. The Lock-Out Die really works. Your Editor uses it on his RCBS 2000 progressive press. I can affirm that a Lock-Out Die has “saved my bacon” a half-dozen times over the years when there was an over-charge (which could cause a Kaboom) or a low charge (which could cause a squib load).
The Lock-Out Die works by using a central die detection rod that sets its vertical position based on the height of the powder column in the case. Through an ingenious design, if the powder column height is too low or too high, the rod locks in place as you start to pull the press handle. This halts the press before the ram can lift and the cartridge plate can advance. Unlike a beeping alarm system (which can be ignored or defeated), the Lock-Out Die physically stops the movement of the press ram and prevents a bullet being seated in the “problem” case.
It takes a bit of tweaking to get the Lock-Out Die detection rod setting just right, but once it is correctly positioned, the Lock-Out Die works smoothly in the background. The Lock-Out Die won’t interfere with the loading process unless it detects a high or low charge — and then it positively stops the progressive loading cycle.
While crafted for use in RCBS progressive presses, the RCBS Lock-Out Die can also be used on a Dillon XL Progressive (see video below) or Hornady Lock-N-Load progressive — though it does take up one station which could otherwise be used for a final crimp die (after the seating die). The RCBS 2000 has one more station than a Dillon 550/650, so it’s an ideal platform for using the Lock-Out Die.
Learn More at UltimateReloader.com
On the UltimateReloader.com website, run by our friend Gavin Gear, you’ll find an excellent two-part series on the function and set-up of the RCBS Lock-Out Die. Part One explains how the Lock-Out Die functions, using cut-away illustrations. Part Two shows how to install and adjust the Lock-Out Die on various progressive presses. The Ultimate Reloader video at the top of this article shows setup of the RCBS Lock-Out Die on the Dillon XL-650 progressive press, while the Reloading Bench video below shows the Lock-Out Die on a Hornady LnL progressive.
Apparently reducing static charges on and around electronic scales can reduce their propensity to drift, lessening the problem of “wandering zero”. Just how and why static charges interfere with scale performance is unclear, but many shooters have noticed that static electricity can cause electronic scales to behave strangely. So how do you reduce static charges around your digital balance? Our late friend German Salazar (aka “GS Arizona”), creator of the Rifleman’s Journal Blog, found a very simple solution — an anti-static aerosol spray — that, by all indications, actually works. When this “spray-can solution” was suggested to German by a fellow shooter, German was skeptical. However, he tried the stuff and he says that it really does help the scale maintain zero over time, with much less observed drift.
Popular Cartridge Types Profiled
Quick Tip: Try Flipping Your Bushings
If you load pistol or rifle ammo with a progressive press, we strongly recommend you get a Lock-Out Die from RCBS. This unique reloading die will prevent your progressive press from advancing if the dispensed powder charge is more or less than about 0.3 grains too high or too low. The Lock-Out Die really works. Your Editor uses it on his RCBS 2000 progressive press. I can affirm that a Lock-Out Die has “saved my bacon” a half-dozen times over the years when there was an over-charge (which could cause a Kaboom) or a low charge (which could cause a squib load).
