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.
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.
Are you a do-it-yourself kind of guy with a creative eye? Then you’ll love the FREE Target Generator from the folks at ShooterShed.com. This FREE, interactive webpage allows you to design a variety of fun targets, including grids, benchrest-type Score/Group Shooting targets, sight-in targets, and even playing card targets. Choose the paper size and orientation (vertical or horizontal), then select the number of target elements on the page. For example, you could have four (4) bulls or a dozen playing cards. Then click the Style TAB to choose your target style. Use the OPTIONS TAB to overlay a grid on the target, choose squares or diamonds, or include load information blocks. For bullseye targets, you can control the number, color, and spacing (diameter) of the rings. LINK to TARGET GENERATOR.
QWIK TIP: For Super-Quick Target Creation, click the “Target Style” tab, then select a design from the list on the left. Then go to OPTIONS.
Click the TARGET STYLE TAB to select one of many target styles, including NBRSA Benchrest targets and 20+ types of NRA bullseye targets, scaled to distance:
Benchrest
Bullseye
Shapes
NRA High Power
NRA Pistol
NRA Rimfire
Images
Playing Cards
Load Test Blocks
Competitors can create practice targets similar to their match targets. This target features short-range range Benchrest competition-style box/circle aiming points, along with fields for entry of gun/load data:
Creating new targets is fast and easy. No computer graphics skills required! We created this green diamonds grid target in just five minutes using the ShooterShed Target Generator:
The program provides a preview of each target you generate. There are controls to choose border and fill colors. If you like a particular design, save the file, and then print as many targets as you want. Check it out, this program is fun and handy to use. Here are four (4) targets your Editor created just for this article. With a bit of practice, you can be generating your own custom targets in minutes.
About the Creator of the Target Generator
The Target Generator program was created by Rod Brown of Sheridan, Wyoming. Rod tells us: “I build custom rifles… I’ve got a 100-yard range out my back door. I shoot short- and long-range benchrest competitively around the country. I’m a full-time software development consultant and an FFL holder. When I’m not developing custom software for my clients, I’m usually fiddling in the shop, building a custom benchrest rifle, traveling to a match, chambering a barrel, or reloading some ammunition.”
Story tip from Boyd Allen. We welcome reader submissions.
This popular video, viewed 3.9 million times on YouTube, provides a clear explanation of Minute of Angle (MOA) and how that angular measurement is used. Among novice shooters, there is much confusion over this term. In this NSSF Video, Ryan Cleckner, a former U.S. Army Sniper Instructor, defines the term “Minute of Angle” (MOA) and explains how you can adjust for windage and elevation using 1/4 or 1/8 MOA clicks on your scope. This allows you to sight-in precisely and compensate for bullet drop at various distances.
For starters, Ryan explains that, when talking about angular degrees, a “minute” is simply 1/60th. So a “Minute of Angle” is simply 1/60th of one degree of a central angle, measured either up and down (for elevation) or side to side (for windage). At 100 yards, 1 MOA equals 1.047″ on the target. This is often rounded to one inch for simplicity. Say, for example, you click up 1 MOA. That is roughly 1 inch at 100 yards, or roughly 4 inches at 400 yards, since the target area measured by 1 MOA increases in linear fashion with the distance.
More Minute of Angle (MOA) Explanatory Videos
This Gunwerks video explains that Minute of Angle subtends approximately 1″ for each 100 yards (well, 1.047″ to be more precise). That means a Minute of Angle increases in actual measured size the greater the distance of the target from the shooter.
This lengthy (24-minute) video defines Minute of Angle, and uses multiple diagrams to illustrate how MOA angular measurements works. The video also how MOA-based click values translate to point-of-impact changes at various distances.
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.
Walker’s has a new line of reduced-size Razor Junior Electronic Muffs for younger shooters. Built specifically for smaller head sizes, the muffs’ compact design ensures a proper seal with less bulk. These new Junior Muffs feature a certified Noise Reduction Rating (NRR) of 23dB, with the same durability as larger adult muffs. The new Junior muffs have a padded folding headband with a sturdy metal wire frame and low-profile ear cups. These Junior Muffs also feature nice, recessed volume control knobs.
Designed to deliver full-size performance in a smaller package, Walker’s Razor Junior Muffs provide young shooters with dependable NRR 23 protection, clear sound, and all-day comfort. This design provides a lightweight, low-profile muff that’s comfortable for hours of continuous use. These muffs are currently offered in five (5) colors: Black, Flat Dark Earth, Gray, Teal (light turquoise blue), and Dark Gray/Pink.
Walker’s Razor Junior Electronic Muffs Features
Dual Hi-Gain omnidirectional microphones capture sound from every direction and pair with full dynamic range HD speakers to deliver crisp, balanced audio. Low-noise, frequency-tuned circuitry preserves natural, distortion-free sound quality, allowing young users to clearly hear everything from nearby conversations to range commands while maintaining situational awareness. At the same time, a sound-dampening composite housing paired with lightning-fast 0.02-second sound-activated compression provides great protection from instant noise spikes. These muffs operate on two (2) AAA batteries.
Now available for purchase online and through retailers nationwide, the youth-sized Razor Junior Muffs deliver excellent protection at a modest price — $47.99 at MidwayUSA. NOTE: These Walker’s compact muffs are also suitable for smaller adult female shooters with a smaller head size than men.
Barrel-maker Dan Lilja’s website, RifleBarrels.com has an excellent FAQ page that contains a wealth of useful information. On the Lilja FAQ Page you’ll find answers to many commonly-asked questions. For example, Dan’s FAQ addresses the question of barrel life. Dan looks at factors that affect barrel longevity, and provides some predictions for barrel life, based on caliber, chambering, and intended use.
NOTE: This article was very well-received when it was first published. We are reprising it for the benefit of readers who missed it the first time.
Dan cautions that “Predicting barrel life is a complicated, highly variable subject — there is not a simple answer. Signs of accurate barrel life on the wane are increased copper fouling, lengthened throat depth, and decreased accuracy.” Dan also notes that barrels can wear prematurely from heat: “Any fast varmint-type cartridge can burn out a barrel in just a few hundred rounds if those rounds are shot one after another without letting the barrel cool between groups.”
Q. What Barrel Life, in number of rounds fired, can I expect from my new barrel?
A: That is a good question, asked often by our customers. But again there is not a simple answer. In my opinion there are two distinct types of barrel life. Accurate barrel life is probably the type most of us are referencing when we ask the question. But there is also absolute barrel life too. That is the point where a barrel will no longer stabilize a bullet and accuracy is wild. The benchrest shooter and to a lesser extent other target shooters are looking at accurate barrel life only when asking this question. To a benchrest shooter firing in matches where group size is the only measure of precision, accuracy is everything. But to a score shooter firing at a target, or bull, that is larger than the potential group size of the rifle, it is less important. And to the varmint hunter shooting prairie dog-size animals, the difference between a .25 MOA rifle or one that has dropped in accuracy to .5 MOA may not be noticeable in the field.
The big enemy to barrel life is heat. A barrel looses most of its accuracy due to erosion of the throat area of the barrel. Although wear on the crown from cleaning can cause problems too. The throat erosion is accelerated by heat. Any fast varmint-type cartridge can burn out a barrel in just a few hundred rounds if those rounds are shot one after another without letting the barrel cool between groups. A cartridge burning less powder will last longer or increasing the bore size for a given powder volume helps too. For example a .243 Winchester and a .308 Winchester both are based on the same case but the .308 will last longer because it has a larger bore.
And stainless steel barrels will last longer than chrome-moly barrels. This is due to the ability of stainless steel to resist heat erosion better than the chrome-moly steel.
Barrel Life Guidelines by Caliber and Cartridge Type
As a very rough rule of thumb I would say that with cartridges of .222 Remington size you could expect an accurate barrel life of 3000-4000 rounds. And varmint-type accuracy should be quite a bit longer than this.
For medium-size cartridges, such as the .308 Winchester, 7×57 and even the 25-06, 2000-3000 rounds of accurate life is reasonable.
Hot .224 caliber-type cartridges will not do as well, and 1000-2500 rounds is to be expected.
Bigger magnum hunting-type rounds will shoot from 1500-3000 accurate rounds. But the bigger 30-378 Weatherby types won’t do as well, being closer to the 1500-round figure.
These numbers are based on the use of stainless steel barrels. For chrome-moly barrels I would reduce these by roughly 20%.
The .17 and .50 calibers are rules unto themselves and I’m pressed to predict a figure.
The best life can be expected from the 22 long rifle (.22 LR) barrels with 5000-10,000 accurate rounds to be expected. We have in our shop one our drop-in Anschutz barrels that has 200,000 rounds through it and the shooter, a competitive small-bore shooter reported that it had just quit shooting.
Remember that predicting barrel life is a complicated, highly variable subject. You are the best judge of this with your particular barrel. Signs of accurate barrel life on the wane are increased copper fouling, lengthened throat depth, and decreased accuracy.
Benchrest Barrel Life — You May Be Surprised
I thought it might be interesting to point out a few exceptional Aggregates that I’ve fired with 6PPC benchrest rifles with barrels that had thousands of rounds through them. I know benchrest shooters that would never fire barrels with over 1500 shots fired in them in registered benchrest matches.
I fired my smallest 100-yard 5-shot Aggregate ever in 1992 at a registered benchrest match in Lewiston, Idaho. It was a .1558″ aggregate fired in the Heavy Varmint class. And that barrel had about 2100 rounds through it at the time.
Another good aggregate was fired at the 1997 NBRSA Nationals in Phoenix, Arizona during the 200-yard Light Varmint event. I placed second at this yardage with a 6PPC barrel that had over 2700 rounds through it at the time. I retired this barrel after that match because it had started to copper-foul quite a bit. But accuracy was still good.
We talked with the experts at Bartlein Barrels. They confirmed that they have seen many, many more barrels harmed by crown damage caused by improper cleaning than by anything else. If you use a bronze brush, Bartlein recommends that you REMOVE the BRUSH after it passes through the muzzle. This is because the bristles take a set (pointing to the breech) during the out-stroke. In other words the bristles angle back as you push towards the muzzle from the breech. If you drag the brush backwards at the muzzle, you force these bristles to reverse direction abruptly right as they cross the delicate crown. In time, that can damage the crown. NOTE: John Krieger of Krieger Barrels also advises his customers not to pull a bronze brush backwards across the crown.
Response to Skeptics
Whenever we’ve published similar advice, given by guys who are producing some of the most accurate barrels in the world, some readers get extremely angry. They say, “You’re crazy! I’ve was pullin’ triggers when you were still in diapers. I’ve got Hall of Fame points and I say there’s no way a phosphor bronze brush can ever do anything to steel. You’re full of it.” Well, these guys are entitled to their opinion. But here’s our response. Number one, we’re just telling you what the barrel-makers are telling US. Don’t kill the messenger. Number two, many of the guys who say bronze brushes can’t affect the crown are the same guys who feel they need to recrown their barrels every 400-500 rounds (Do we see a connection?). Third, if you don’t think a softer material can affect steel, look at the steel ferrules of a well-used fishing rod — there the steel is worn away by plastic. (With time, water will wear away granite.) Lastly, this Editor can tell you I’ve seen the damage myself, first-hand, using a magnifying glass on much-brushed benchrest barrels. Right at the muzzle, the top edge of the lands had sharp, jagged edges that looked like little shark’s teeth, or the edge of a serrated knife. By contrast, a new barrel will have a nice, smooth straight edge along the top of the lands at the muzzle.
Also Be Careful with Jags
Bartlein’s experts also told us to be careful about the jags you use. Dewey-style jags in particular can cause problems. These have a long shaft with multiple rings with diamond-pattern “teeth”. The teeth are designed to grip a patch. The problem is that the lower rings may be exposed below the patch fabric, so the teeth can grind directly on the rifling and/or crown. Bartlein says Dewey-style metal jags can damage a crown very quickly if any of the toothed rings are exposed, metal-on-metal. Tim North of Broughton barrels also advises against using the Dewey-style jags with toothed rings. Interestingly, Dewey uses the same type of diamond-shaped teeth on the bottom of its “Crocogator” primer pocket tool, so you know those knurled teeth can scrape.
Readers often ask “What’s the difference between a Weaver scope rail and a Picatinny Rail?” The answer is not as simple as it seems. The dimensions of a Picatinny Rail should be consistent (from one rail-maker to another), since there IS a government spec. Conversely, there is some variance in “Weaver-style” rails. The width of the groove is the most important difference between Picatinny Rails and Weaver-type rails. “Mil-spec” Picatinny rails will have a grove width of 0.206″ while Weaver rails typically have a narrower, 0.180″ groove width.
Does your rifle have a Weaver Rail or Picatinny Rail? Check the dimensions to be sure.
A while back, Brownells had a helpful GunTech™ Article that discussed the Picatinny Rail vs. Weaver Rail. That article explained:
What are the differences between the ‘Picatinny’ and the ‘Weaver’ systems? The profile of the two systems is virtually identical. Depending on the quality of the machining done by the manufacturer, the two systems should be indistinguishable from the profile. The key difference lies in the placement of the recoil grooves and with width of the grooves. MIL-STD-1913 (Picatinny) grooves are .206″ wide and have a center-to-center width of .394”. The placement of these grooves has to be consistent in order for it to be a true Picatinny MIL-STD system. Weaver systems have a .180” width of recoil groove and are not necessarily consistent in a center-to-center measurement from one groove to the next.
In many instances, a Weaver system has a specific application that it is machined for, so interchangeability is not necessarily an issue. A MIL-STD-1913 system must adhere to the specifications listed above in order for it to be considered MIL-STD, since the military desires uniformity in the recoil grooves to allow for different systems to be mounted on the weapon with no concern for compatibility.
Now, what does this mean? Boiled down, it means that accessories designed for a Weaver system will, in most cases, fit on a Picatinny system. The reverse, however, is probably not the case. Due to the larger recoil groove, Picatinny accessories will not fit a Weaver system. There are, of course, exceptions to every rule, but for a good rule-of-thumb, [full-width] Picatinny won’t fit Weaver, but Weaver accessories WILL fit Picatinny.
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 regularly for other, helpful reloading and marksmanship 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.
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!
This video explains the procedure for ordering an M1 Garand from the CMP.
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.
