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February 20th, 2024

High-Quality Cartridge Diagrams — Download for FREE

Winchester centerfire rimfire pistol shotshell ammo ammunition cartridge diagram illustration

Winchester’s new “Introduction to Ammunition — Ammo 101” is a four-part series including custom illustrations and information for four major ammunition categories: rifle, pistol, rimfire, and shotshell. The Ammo 101 series provides a detailed overview of centerfire rifle, centerfire pistol, rimfire, and shotshell ammunition, showcasing ammunition construction, components, calibers, and common usage. The Ammo 101 resource is free to download from Winchesters.mediaassets.com. Or, simply click one or more diagrams below. Each image will launch a large PDF which you can print or download.

TIP: Click Each Image for Full-Screen Printable PDF

Shown below are the first four ammunition information sheets prepared by Winchester. These show all the key components of cartridges and shotshells, and explain the functions. These diagrams are useful for training, and for persons getting started in reloading.

Ammo 101 Centerfire Rifle Cartridge Diagram (click for PDF)

Winchester centerfire ammo ammunition cartridge diagram illustration

Ammo 101 Rimfire Cartridge Diagram (click for printable PDF)

Winchester centerfire ammo ammunition cartridge diagram illustration

Ammo 101 Pistol Cartridge Diagram (click for printable PDF)

Winchester centerfire ammo ammunition cartridge diagram illustration

Ammo101 Shotshell Diagram (click for printable PDF)

Winchester centerfire ammo ammunition cartridge diagram illustration


CLICK HERE for ALL FOUR Diagrams in SINGLE LARGE PDF »

About the Ammo 101 Series
The FREE Ammo 101 resources can help instructors nationwide who introduce new entrants to the shooting sports and hunting. Instructors can incorporate these resources into their training presentations, use them as handouts, or have them printed locally.

“The basics of ammunition… is what we want to deliver with the Ammo 101 series,” said Matt Campbell, Winchester V.P. of Sales & Marketing. “With millions of people across the United States starting their journey in the shooting sports as new firearm owners, providing easy-to-understand information on ammunition types is one way we can help educate our customers.”

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February 15th, 2024

Bird’s Eye View via Aerial Drone — Hitting Steel at 1122 Yards

Texas .223 Rem Drone Video 1000 Yards Gorilla Ammo

Many of our readers have never had a chance to shoot much past 600 yards. How far away does a 1000-yard+ target really seem to the naked eye? Well this short video answers that question. Gorilla Ammo, the video’s producers, used a camera-carrying aerial drone to fly downrange from the firing line all the way out to 1122 yards (and back again). Watch the drone footage at 0:00-0:07 and especially 0:48-1:03. The “bird’s-eye view” really gives you a sense of the distance. The “fly-back” at 0:48-1:03 time-mark is what makes this video worth watching.

The video features prone shooting at steel targets placed at 750 and 1122 yards. We do apologize for the lame, “oh so serious” voice-over which attempts to make this rather ordinary range session seem like some kind of life-changing experience. (Frankly, you may just want to turn the sound off — it’s that annoying.) It’s really not that big a deal to hit steel at 750 yards with a quality AR-15, chambered in .223 Rem, shooting Sierra 77 grain MatchKings.

Texas .223 Rem Drone Video 1000 Yards Gorilla Ammo

Hitting Steel at 1122 Yards with 2540 FPS Ammo Can Be Challenging
The 1122-yard hits are a bit more impressive. Gorilla Ammo lists a relatively sedate 2540 fps Muzzle Velocity for its .223 Rem 77gr SMK ammunition. According to JBM Ballistics, at 1125 yards, that 2540 fps load has 68.3 MOA of drop from a 100-yard zero (firing at sea level and 80° F ambient). Moreover the bullet goes trans-sonic around 750 yards (losing stability) and is traveling just 933 fps at impact. And the wind’s the killer — at 1125 yards, with this bullet/load, a mere 2 mph, full-value wind change can move the Point of Impact over three feet!

Permalink - Videos, Shooting Skills, Tactical No Comments »
December 31st, 2023

Safety Considerations When Using Progressive Presses — USAMU

Accurateshooter.com USAMU progressive press reloading

For many years, the U.S. Army Marksmanship Unit (USAMU) regularly published reloading “how-to” articles on the USAMU Facebook page. In this article, the USAMU’s reloading gurus address a question frequently asked by prospective handloaders: “Should I buy a single-stage press, or a progressive?” The USAMU says the best answer is Solomon-esque in both its wisdom and simplicity: “Get BOTH!” However, there is definitely more to the issue, as the USAMU explains below.

USAMU Reloading

Progressive Press Safety Considerations

by USAMU Staff
Many are the beginning handloaders who have asked a friend about their “setting up” a progressive press for them. The idea is that the newbie could then just feed in components and crank out buckets of practice ammo without needing to really learn much about handloading. Tempting though this might be, that’s simply not how it works. Such an approach might be ok if there were never a malfunction with either press or operator, but that’s unrealistic. Our hypothetical newbie would then lack the knowledge to problem-solve most situations.

usamu progressive reloading press RCBS

Worse yet, several different handloading operations would be occurring at different stations on the progressive press at the same time. It takes an experienced operator to keep track of, and truly understand the significance of, all those potential mini-problems. Loading without this experience is a recipe for potential disaster – such as a double powder charge (especially with pistol cartridges) dropped while the loader was attending to some other function, etc. Progressives are an animal unto themselves, and while they offer many benefits, they do take some getting used to – even by experienced handloaders!

ILLUSTRATIVE HORROR STORY
Here, enter a 40-year veteran handloader who decided to jump onto the progressive bandwagon late in his career, having used only single-stage presses all his life. A High Master NRA High Power Rifle competitor, he had no background in competitive pistol shooting, where historically most progressive presses are found.

Experienced Action Pistol shooters have typically encountered multiple episodes in which shooters “skipped” a powder charge for some reason, leading to a squib round and a bullet possibly lodged in the bore. Thus, at matches, it’s reflexive for them to yell “STOP!” in unison if they see a shooter get a “click” vs. a “bang”, and rack the slide to keep firing. This writer has personally seen several pistols saved in just such scenarios over the years.

Click No Bang — What NOT to Do
Our High Master set up a popular progressive press and began turning out .223 Rem 100-yard practice ammo with abandon. He was using a moly-coated 52gr match bullet and an economical, fast-burning surplus powder that gave great accuracy. Once on the range, he began practicing strings of rapid-fire. All was well, until he heard “Click!” rather than “Boom”.

Lacking the above experience or onlookers to halt him, he reflexively operated the charging handle on his expensive, custom NM AR15 Service Rifle, and the next trigger squeeze reportedly registered on seismographs over at least a three-state radius. He sat, uninjured but bewildered, until the hail of expensive bits and pieces quit raining down around him.

When the smoke cleared, he immediately cursed the horrid, evil, demonically-possessed progressive press for this, his first-ever reloading mishap. His $1400 NM upper was ruined, but thankfully, his $800 pre-ban lower… and he had escaped injury.

This tale is told not to discourage the use of progressive presses, but to emphasize the need to EASILY and IMMEDIATELY KNOW what is happening with the press at each station, every time the handle is cranked. Not to do so is, as they say, “bad ju-ju.”

It illustrates why we at the USAMU Handloading Shop agree in recommending that new handloaders should begin with a single-stage press. Once one thoroughly learns the steps in each phase of handloading by repeated experience, then one will be qualified to move on to a progressive press.

The single-stage press will REMAIN virtually indispensable for one’s entire handloading career, even after having purchased a progressive press (or two). There are endless small projects that are best handled on a single-stage press, and a poll of USAMU’s Handloading staff reveals that not one would willingly be without his single-stage press, despite owning at least one progressive.

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November 14th, 2023

Save Money Shooting ARs — .22 LR Rimfire Conversion Kits

.22 LR 22LR rimfire AR AR15 AR-15 conversion kit bolt magazine savings ammo ammunition

With inflation, the increased cost of .223 Rem centerfire ammo has driven more folks to shooting .22 LR rimfire ammo, both for fun and practice. Thankfully, handy conversion kits will let you shoot .22 LR ammo from your existing .223/5.56 AR-15 platform rifle. This allows low-cost training with no change in rifle balance, ergonomics, and/or optics.

The CMMG Bravo .22 LR Conversion Kit provides a replacement bolt/bolt carrier along with three 25-round magazines with special .22 LR-fitted followers and ammo slots. This allows you to shoot rimfire ammo from any AR-15 chambered for the .223 Rem (5.56×45). The CMMG Bravo has an integrated extension that fits into your current chamber. The rimfire bullet passes through this extension and then enters the barrel. This conversion kit is now on sale at Brownells for $179.99 with three 25-rd mags.

.22 LR 22LR rimfire AR AR15 AR-15 conversion kit bolt magazine savings ammo ammunition
The CMMG Bravo conversion Kit comes with blowback-operated .22 LR bolt carrier, rubber protector for bolt carrier tip, and three 25-round polymer magazines. To use, simply replace the rifle’s .223 Rem bolt and carrier with the Bravo .22 LR conversion unit and load up the included magazine(s) with rimfire ammo.

To use the CMMG Kit, simply remove the centerfire bolt/bolt carrier, and replace it with the CMMG silver colored bolt shown above. CMMG states: “For best performance use a round-style hammer as notched hammers can cause function issues.” Testers have stated that high-velocity .22 LR ammo works best, and CMMG notes that “36gr plated-nose bullets have proven to be the best choice for function.” The copper-plated bullets help reduce fouling.

Ultimate Reloader Tests CMMG .22 LR Conversion Kit

Our friend Gavin Gear of UltimateReloader.com recently tested the CMMG .22 LR AR Conversion Kit. He observed that installation was very straight-forward and the CMMG magazines worked well. He and fellow tester Travis Fox shot the unit both slow-fire and rapid-fire successfully.

Gavin and Travis found the CMMG Kit easy to install and fun to use. With an AR that can shoot both .223 Rem and .22 LR, it’s like having “two guns in one”. Travis was impressed with the ease of use: “It is so simple to change over to the CMMG .22 LR AR kit! It took me about 68 seconds the very first time I tried. Each time after that it took me about 40 seconds — it’s that simple. It takes longer to fully load one of the mags than it does to switch over from .223/5.56 to .22 LR and back.”

The AR shot very well with the higher-velocity ammo types. 100% functioning was achieved with both 40gr Federal Game Shok ammo and American Eagle High Velocity 38gr Copper-plated HP ammo. NOTE: CMMG does recommend high-velocity Copper-plated rimfire ammunition.

Maintenance Tip — After converting back to your centerfire .223 Rem (5.56), Travis says “make sure to clean the gas tube and components as .22 LR tends to run dirty”. READ Full Test on UltimateReloader.com.

CMMG Bravo Conversion Kit Gets Thumbs Up from Gavin and Travis
“Does this conversion kit get the Ultimate Reloader stamp of approval? Absolutely! In these times of ammunition/component scarcity this gives options to shooters. Finding bulk .22 LR can sometimes be easier than 223/5.56. This kit gives that option at a great price. Any chance to keep skills up and familiarize new shooters to a platform is a good thing. Basically two rifles for a lot less than another rifle.”

.22 LR 22LR rimfire AR AR15 AR-15 conversion kit bolt magazine savings ammo ammunition

How to Install CMMG Bravo .22 LR Conversion Kit

The Brownells video below shows the installation process step-by-step:

In this instructional video, a Brownells gunsmith demonstrates (step by step) how to install, disassemble, clean, lubricate, and reassemble the CMMG AR-15 .22 LR Conversion Kits. Clear the rifle and make safe before you start the conversion. Separate the upper and lower, remove the standard bolt carrier group. You then install the conversion bolt and connect the upper and lower as normal.

Details of CMMG .22 LR Conversion Kit

.22 LR 22LR rimfire AR AR15 AR-15 conversion kit bolt magazine savings ammo ammunition

“For years I’ve had a CMMG conversion kit. It’s a drop-in system that’s … very reliable and it’s accurate. The [CMMG conversion] has lower recoil [and is] great for training. Even though ammo prices have gone through the roof, .22 LR is still cheaper to shoot than anything else.” — SootchGear

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November 8th, 2023

.308 Win vs. 6BR vs. .223 Rem — Recoil Energy Comparison Chart

6mmBR NormaMany visitors to the site ask us, “I’ve got a .223 and .308. What will a 6mmBR Norma (6BR) give me that I’m not getting already?” Well first you will probably average consistently smaller groups than your current .223 or .308 rifle (assuming the 6BR has a quality barrel and trigger). A good .308 Winchester can be superbly accurate, no question about that, but the lesser recoil of the 6BR works in the shooter’s favor over a long string of fire. Even with a Rem 700 or Savage action factory action, a 6BR with a benchrest stock, premium barrel, and a high-quality chambering job should deliver 5-shot groups in the high twos to mid-threes, provided you do your job. We have one 6BR rifle that shoots Lapua factory-loaded 6BR ammunition in the low twos and high ones. That’s exceptional, we admit, but it still shows how the 6BR is an inherently accurate cartridge, even with factory loads.

Compared to a .223, the 6BR offers a much better selection of high-BC projectiles, and will deliver considerably more power on the target. So it’s a better choice for hunters and 600-yard benchrest shooters. Compared to the .308 Win shooting 168gr MatchKings, a 6BR shooting 105-107gr bullets offers better ballistics all the way out to 1000 yards. Plus, for most people, the 6BR is just easier to shoot than a .308 Win. Recoil is less than half of the .308 Win cartridge. Both the .308 and 6BR chamberings offer good barrel life, but the 6BR uses 15-18 grains less powder, saving you money. On the other hand the .308 Win is the designated cartridge for F-TR and Palma shooting, so it may be a more versatile chambering for Long-Range competition. So which would we choose between the 6BR and the .308? Actually we think you should have both. The 6BR is a favorite cartridge out to 500 yards, and we like the .308 Win for F-TR. The .308 Win has shown outstanding accuracy, as displayed last week at the NRA F-class Nationals in Arizona.

Permalink Gunsmithing, Tech Tip No Comments »
October 25th, 2023

Learn How to Upgrade and Customize AR-15 Platform Rifles

AR AR15 Armalite Black Rifle Book Gun Digest
Photo Courtesy Cabela’s Gun Sports

Kevin Muramatsu’s black rifle book, the Gun Digest Guide to Customizing Your AR-15, is a great resource for fans of AR-platform rifles. All the AR options you can imagine are covered: suppressors, premium barrels, adjustable stocks, free-float handguards, ergonomic grips, buffer systems, tactical lights and much more. Those planning an AR rifle build will find application-specific suggestions for 3-Gun, Service Rifle, High Power (Space Gun), Hunting, and Self-Defense use.

AR AR15 Armalite Black Rifle Book Gun Digest AR AR15 Armalite Black Rifle Book Gun Digest

Firearms expert Muramatsu offers advice on choosing the right stock/barrel/optics configuration for your particular game. He also discusses the wide variety of options for slings, grips, magazines and other accessories. With over 520 photos, the book includes a large photo gallery of customized ARs, and includes bonus coverage of the FAL and other “tactical” firearms. The Gun Digest Guide to Customizing Your AR-15 is available from Amazon.com (#ad) for $35.95, and a Kindle eBook version is offered for $14.99. The book is also sold by Barnes & Noble, and most other major booksellers.

As an Amazon Associate, this site earns from qualifying purchases.

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August 25th, 2023

Modern F-TR Rifle with Borden Action, Krieger Barrel, SEB Bipod

F-TR Rifle laminated stock X-Ring Borden Action SEB Joy-Pod
A carpet is used up front for smoother tracking with the Joy-Pod’s flat, ski-style feet. The arms of the Joy-Pod were painted to match the stock. The rear bag features low-drag material on the ears.

F-Class competition grows in popularity every year. Unlike F-Open, the F-TR (Target Rifle) class is limited to the .223 Remington (5.56×45) or .308 Winchester (7.62×51) chamberings. F-TR rifles also use bipods rather than a front rest. But these are no ordinary Harris-style bipods. Modern F-TR bipods have a wide footprint for added stability and many F-TR shooters favor SEB Co-Axial joystick bipods (aka “Joy-Pods”). Today we are featuring an F-TR rig that showcases the types of components, and accessories used by top F-TR competitors — including a coaxial bipod and Labradar Chronograph. If you’re considering getting started in the F-TR game, take a close look at this modern F-TR build from Forum member DM.Oakes.

F-TR Rifle laminated stock X-Ring Borden Action SEB Joy-Pod

Modern F-TR Rig with Borden Action, Krieger Barrel, and SEB Joy-Pod
This handsome .308 Win F-TR rig features a smooth-running Borden BRM action, 30-inch 1:10″-twist Krieger barrel, and an X-Ring Laminated Wood stock. Up front is a coaxial “Joy-Pod” joystick bipod. This is a state-of-the art, wide footprint bipod used by many competitors at the Worlds in Canada. The long joystick allows the “driver” to quickly adjust both elevation and windage in a smooth, continuous motion. The Joy-Pod can be adjusted so it will hold setting during the shot — you don’t have to “hard-hold” the joystick. Many shooters let the joystick slide through their fingers as the rifle moves back on recoil. With a little practice (and careful placement of the rear sand-bag), the tracking is excellent and you can slide the gun right back to point of aim after each shot.

Action: Borden BRM
Trigger: Blue-printed Jewell BR
Barrel: Krieger 30″ / 4-Groove / 1:10″ twist (.30 Cal)
Chamber: .308 Winchester with 0.170 Freebore
Stock: X-Ring Laminated F-Class
Scope: Nightforce 12-42x56mm Competition
Potential Name: Blue Thunder

F-TR Rifle laminated stock X-Ring Borden Action SEB Joy-Pod
This F-TR rifle is shown during load testing with a LabRadar chronograph.

» Full LabRadar Field Test/Review by Ray Gross

If you are considering purchasing a LabRadar Chronograph system, we strongly suggest you read the very thorough and informative LabRadar Review by Ray Gross, past Captain of the USA F-TR team. Ray notes: “It takes me about 3 minutes to set up [my LabRadar] at the range. Because there are no downrange screens, I do not have to hold up other shooters on the range like I would when setting up a traditional chronograph. The convenience alone will mean that I will use it more often than my old chronograph. Every time I take it out, I enjoy it a little bit more.”

Bart Sauter Ray Gross LabRadar Benchrest Review Chronograph Bench tripod

Permalink Competition, Gear Review No Comments »
July 20th, 2023

.300 Blackout Fired in .223 Rem AR — Recipe for Disaster

.300 AAC Blackout 300 BLK kaboom accident blowup cartridge failure barrel .223 Rem 5.56
Photos and Facebook post by Tactical Rifle Shooters

Yet another .300 Blackout disaster. Unfortunately, that .300 Blackout cartridge can fit in a .223 Rem chamber. Shooting a .308-caliber bullet in .223 bore is a recipe for disaster.

.300 AAC Blackout 300 BLK kaboom accident blowup cartridge failure barrel .223 Rem 5.56

.300 AAC Blackout 300 BLK kaboom accident blowup cartridge failure barrel .223 Rem 5.56The .300 AAC Blackout aka “300 BLK”, is a compact 30-caliber cartridge designed to work in AR-15 rifles. It has a shorter cartridge case to accommodate the bigger 30-caliber bullet while still fitting in a standard AR-15 magazine. Unfortunately, that’s the danger. A careless shooter can toss a .300 Blackout cartridge in with .223 Rem rounds without noting. And because the case-head size is the same as the .223 Rem (5.56×45) the rifle’s bolt assembly will happily chamber and fire the .300 BLK round. Problem is, that forces a .308 diameter bullet down an undersized .223-caliber bore. Not good!

This images were provided by Tactical Rifle Shooters on Facebook. The message was clear: “Don’t try to run 300 Blackout in your .223/5.56mm. It won’t end well. The problem is identical rifles and identical magazines but different calibers.”

Image from Accurate Shooter Forum. Cutaway shows the jammed .30-Cal bullet:
.300 AAC Blackout 300 BLK kaboom accident blowup cartridge failure barrel .223 Rem 5.56

For those who MUST have a .300 Blackout, here are some things you can do:

1. Use different colored magazines for .300 Blackout vs. .223 Rem.
2. Fit all your uppers with caliber-labeled ejection port covers.
3. Mark .223 Rem upper handguards with the caliber in bright paint.
4. Mark all .300 BLK Rounds with heavy black marker.

.300 AAC Blackout 300 BLK kaboom accident blowup cartridge failure barrel .223 Rem 5.56

Comments by Folks Who Viewed these .300 Blackout Disaster Photos:

“The .300 Blackout is simply a badly-designed round. A properly-designed round would have had a feature in the shape that would have prevented cross loading in the first place.” — D. Santiago

“I almost made that mistake… I had a magazine of 300 BLK inserted in my .223/5.56 all night. Fortunately, I never pulled the trigger. Once I realized the mistake, I almost got ill. [After that incident] I no longer own a 300 BLK.” — B. Welch

“Happened to me hog hunting from a helo. Gun exploded in my face.” — B. Hood

“Fire-forming projectiles [is] so wrong in centerfire!” — M. Stres

“Had some dude come into the store the other day wanting .300 Blackout ammo to shoot in his 5.56 AR. It took 15 minutes of explaining for him to understand you got to have a .300 Blackout Upper!” — R. Williams

Permalink Bullets, Brass, Ammo, Gunsmithing, Tactical, Tech Tip 2 Comments »
July 14th, 2023

Optimal Barrel Twist Rate — Factors to Consider

Glen Zediker Twist Rate .223 Rem Barrel Top Grade Ammo Midsouth
Here’s an extreme range of .224-Caliber bullets: 35gr varmint bullet and 90gr match bullet. Of course, along with bullet length/design, you need to consider MV when choosing twist rate.

Even with the same caliber (and same bullet weight), different bullet types may require different rates of spin to stabilize properly. The bullet’s initial spin rate (RPM) is a function of the bullet’s muzzle velocity and the spin imparted by the rifling in the barrel. You want to ensure your bullet is stable throughout flight. It is better to have too much spin than too little, according to many ballistics experts, including Bryan Litz of Applied Ballistics. The late Glen Zediker put together some basic tips concerning barrel twist rates and bullet stability. These come from Glen’s book, Top Grade Ammo.

Choosing the Right Twist Rate
I’d always rather have a twist too fast than not fast enough. Generally… I recommend erring toward the faster side of a barrel twist decision. 1:8″ twist is becoming a “new standard” for .224 caliber, replacing 1:9″ in the process. The reason is that new bullets tend to be bigger rather than smaller. Don’t let a too-slow twist limit your capacity to [achieve] better long-range performance.

Base your next barrel twist rate decision on the longest, heaviest bullets you choose to use, and at the same time realize that the rate you choose will in turn limit your bullet choices. If the longest, heaviest bullet you’ll shoot (ever) is a 55-grain .224, then there’s honestly no reason not to use a 1:12″. Likewise true for .308-caliber: unless you’re going over 200-grain bullet weight, a 1:10″ will perform perfectly well.

Glen Zediker Twist Rate .223 Rem Barrel Top Grade Ammo Midsouth

Bullet Length is More Critical than Weight
Bullet length, not weight, [primarily] determines how much rotation is necessary for stability. Twist rate suggestions, though, are most usually given with respect to bullet weight, but that’s more of a generality for convenience’s sake, I think. The reason is that with the introduction of higher-ballistic-coefficient bullet designs, which are longer than conventional forms, it is easily possible to have two same-weight bullets that won’t both stabilize from the same twist rate.

Evidence of Instability
The tell-tale for an unstable (wobbling or tumbling) bullet is an oblong hole in the target paper, a “keyhole,” and that means the bullet contacted the target at some attitude other than nose-first.

Glen Zediker Twist Rate .223 Rem Barrel Top Grade Ammo MidsouthIncreasing Barrel Length Can Deliver More Velocity, But That May Still Not Provide Enough Stability if the Twist Rate Is Too Slow

Bullet speed and barrel length have an influence on bullet stability, and a higher muzzle velocity through a longer tube will bring on more effect from the twist, but it’s a little too edgy if a particular bullet stabilizes only when running maximum velocity.

My failed 90-grain .224 experiment is a good example of that: I could get them asleep in a 1:7″ twist, 25-inch barrel, which was chambered in .22 PPC, but could not get them stabilized in a 20-inch 1:7″ .223 Rem. The answer always is to get a twist that’s correct.

These tips were adapted from Glen’s popular 2016 book, Top-Grade Ammo, now $38.95 on Amazon. That work has numerous helpful articles on technical topics. Here are links to this title and other books by Glen Zediker.


Permalink Bullets, Brass, Ammo, Gunsmithing, Tech Tip 1 Comment »
July 11th, 2023

How Accurate Does Varmint Ammo Really Need to Be?

Wyoming varmint hunt prairie dog Sierra Bullets Tommy Todd Reloading accuracy powder measure
Photo by Forum member R. Hardy. View Related Accurate Shooter Forum Thread.

We’re in the middle of summer, so many folks will head to the hinterlands on prairie dog safaris. On a good P-Dog adventure, you may shoot hundreds of rounds over a long weekend. So you’ll need plenty of ammo. With these ammo volume requirements, you probably won’t have time to load to benchrest standards, and you may not have the budget for match-grade bullets. To save time you may throw (rather than weigh) your charges, or even load on a progressive press. This all raises the question of ammo accuracy — how good is “good enough”? A Sierra Bullets expert answers that question here — explaining how to efficiently load ammo for varmint work.

Ammunition Accuracy Requirements 101 — Varmint Ammo

Wyoming varmint hunt prairie dog Sierra Bullets Tommy Todd Reloading accuracy powder measure

This story based on article by Sierra Bullets Chief Ballistician Tommy Todd
I load and shoot ammunition for a living. In my duties here at Sierra I constantly test bullet accuracy for our production needs. Because of this, I shoot a variety of different calibers and cartridges on a daily basis and a large demand of this shooting is keeping the guns and loads tuned for optimum accuracy. I have a very narrow window of tolerances to maintain in order to provide our customers (you) with the most accurate bullets on the market.

I have learned many tricks and techniques over the years to tuning a load, prepping brass, and cleaning barrels to keep a gun shooting. I often utilize the things I have learned and take them to extreme levels when competing in a shooting event. I also often ignore most of these things (other than safety) and simplify the process if the shooting I will be doing does not warrant.

Recently I went on a prairie dog shoot in Wyoming with some good friends. The targets cooperated as did the weather with the exception of some challenging winds we experienced. We had a great time and make a lot of hits on those small rodents. When loading for the .223 Remington rifles and the TC Contender, I cut a few corners in the ammunition-loading process due to both time constraints and accuracy needed. When shooting at a prairie dog a miss is simply that, but when shooting at say the X-Ring at 1000-yard competition, a poorly-placed shot [harms your] placing in the match. Because of this, I can afford to miss an occasional shot at a varmint due to ammunition capability without worry but will not allow the same tolerances in my match ammo. For the Wyoming trip I utilized a powder measure and simply dumped the charges into primed cases that had been full-length sized and primed.

Wyoming varmint hunt prairie dog Sierra Bullets Tommy Todd Reloading accuracy powder measure

I had measured enough for length to know that while there was some variance all were under maximum length. I know there is some variation of the measure I utilized but not significant enough to warrant weighing every charge. When seating the bullets a competition seating die was used and I verified OAL on the occasional cartridge to make sure nothing changed.

This varmint ammo, with thrown charges, put TEN shots inside ONE inch at 200 yards. That’s half MOA. Good Enough? Absolutely!
Wyoming varmint hunt prairie dog Sierra Bullets Tommy Todd Reloading accuracy powder measure

The ammo produced shot under one inch at 200 yards in one of the guns I planned on taking on to Wyoming with me. [Editor: That was for TEN Shots — see above.] I knew I had loaded ammunition that was quite suitable for the task at hand which was evidenced by the number of hits I was able to make at fairly long range.

NOTE: The author, Tommy Todd, explains that, when loading ammo for F-Class matches, he uses more exacting methods. He weighs every charge and seats his bullets carefully with an arbor press. Todd adapts his methodology for his particular application. The lesson here is to load to the level of precision demanded by your discipline. READ Full Story HERE.

Varmint Prairie Dog hunting safari reloading powder measure Tommy Todd

Permalink Bullets, Brass, Ammo, Hunting/Varminting, Reloading No Comments »
July 2nd, 2023

Sunday Gunday: AR Service Rifle — Reloading and Ammunition

High Power service rifle AR15 reloading 600 yard Danny Arnold powder kernels
The 600-yard target has an X-Ring 6 inches (1 MOA) across, while the 10-Ring spans 12 inches (2 MOA).

The following article is about reloading for NRA/CMP Highpower Rifle competition and is geared toward competitors shooting the AR15 Service Rifle. In Highpower Rifle competition, shooters fire in four stages: Standing slow-fire at 200 yards, Sitting rapid-fire at 200 yards, Prone rapid-fire at 300 yards, and Prone slow-fire at 600 yards. Competitors use a sling for support in all positions but standing. A typical AR15 Service Rifle sports a 20″ free-floated barrel and a 4.5-pound trigger. Service Rifle scopes are limited to maximum power of 4.5X.

Thoughts on Loading for Service Rifles, Particularly for 600 Yards

by Danny Arnold, Team CMP
Article originally published in CMP Shooting News

Before we get started, I want to stress that all of the information that follows is geared toward the .223/5.56 Service Rifle. That doesn’t mean that there’s nothing here for anyone else, but the .223/5.56 Service Rifle platform is where I’ve spent the majority of my time, so here we go.

There is only one “Perfect” 600–yard load for my rifle, True or False? This example is more anecdotal than scientific, but it provides some food for thought….

Team CMP spent the early part of March competing in the Orange Blossom Regional. As soon as we got on the range, Sara Rozanski (Team CMP member) started having problems with her 600-yard ammunition. Nearly 1/3 of her cases were exiting the chamber minus the primers. I offered to swap my ammunition for hers, suspecting that my Wylde chamber would be more forgiving than her CLE chamber — a solution that seemed to solve the problem. At least neither of us was blowing primers!

High Power service rifle AR15 reloading 600 yard Danny Arnold powder kernels

Sara’s ammunition was a factory load using a well-known 80+ grain bullet with an unknown primer and powder, using brass from a respected manufacturer. My load was a different brand of 80-grain bullet, with my choice of powder and primer, all in brass made by someone else. Given the color of the primers, the only thing that our ammunition could possibly have had in common was the brand of powder… maybe. So, how did we shoot?

Sara and I shot the two-person team together and the entire 2,400 Aggregate, although on different relays. Sara’s combined 600-yard score was 780-28X (97.5%). Mine was a 783-24X (97.87%). Our scores were never more than two points apart on any of the four days. Keep in mind that we were using each other’s ammunition the entire time.

So, we had different barrels, chambers and ammunition, but similar results. That goes back to the idea that a good load will perform similarly if fired in a good barrel.

Are We Too Focused on Ballistic Coefficients (BCs)?
The revailing wisdom has always trended toward loading the highest-BC bullet we could find and pushing it as fast as possible. Back in the early ’90s when I got started with the AR15, the 80-grain Sierra was state of the art. Actually, I picked up all of my Leg points with it, although today it looks a bit dated — kinda like me.

So, the question I’ll pose is this: Would you rather shoot a high-BC bullet that groups 3/4-MOA (minute of angle) or a lower-BC bullet that groups into one-half-MOA traveling 50 feet-per-second faster? The reason that I posed this question is a situation I found myself in a decade ago. Our coach decided that he wanted us to pair-fire some 600-yard for practice. Unfortunately, I hadn’t gotten the memo and all that I had available was my normal short-line ammunition, loaded with a 77-grain bullet. The shooter I was paired with was using a higher-BC bullet than I was, but in the end, we both shot 198s.

Admittedly, using 77-grainers meant that coach had to work a little harder to keep us together on target, but it was a teaching moment for me. I knew that my upper shot 77s better than the available bullets in the 80-grain range, so I cranked out a windage table for the 77-grain bullet at 600 yards and shot those for the rest of the season. After all, the wind blows ALL bullets around. It’s just a matter of knowing what YOUR bullet is doing.

With the shortages that we’re experiencing right now, a lighter bullet may be all that you have available for the 2021 season. That doesn’t mean that you’re disadvantaged though.

High Power service rifle AR15 reloading 600 yard Danny Arnold powder kernels
Danny Arnold teaching Highpower Clinic at 2021 CMP Eastern Games

Loading High-BC Bullets
In the past decade, several bullets have appeared that weigh 80-grains or more. One thing that many of them have in common is a very sharp nose profile, whether metal or polymer. The question is: Are you using the right seating stem?

The jacket material in the bullet’s nose is very thin. If you section a bullet, you’ll find that there is a surprising amount of air space in the nose. If you’re using older seating dies, your seating stem may be contacting the bullet nose too close to the tip, where the jacket is the both thinnest and is unsupported by the lead core. This can manifest itself either as a deformation at the very tip of the bullet or as a circular dent around the bullet nose that you can see and feel with your thumbnail. I think we can all agree that denting a bullet is usually considered a bad thing.

High Power service rifle AR15 reloading 600 yard Danny Arnold powder kernels

One company goes so far as to recommend their proprietary seating stem for use with their high-BC bullets. Other companies leave it up to you to find a seating stem that will allow the bullet nose to go deeper into the seating stem, moving the contact point further down the bullet where the jacket is thicker and supported by the core material.

Seating Depth and Bullet Preferences
Some bullets don’t mind some “jump” into the lands, but some really do. Unfortunately, manufacturers don’t tell you much about that. Your chamber configuration (Wylde, CLE, or some hybrid of the two) and the bullet that you choose will determine your optimal seating depth. Long and short of it, a quality measuring tool to determine seating depth is a necessity these days. Keep in mind that if you’re doing this with a brand new barrel, the throat is likely going to change slightly in the first 200 rounds and may need to be re-measured. Actually, since all of your short range ammunition has to be loaded to magazine length, you’re probably better off developing your short range loads before starting on long range load development. That gives the throat a chance to wear in a bit on a new barrel.

Brass Prep — Why It Is Important
When match-grade AR15s first arrived on the scene, it was amazing how little it took to get them to shoot well. Other than making sure that I had brass from the same lot and running it through a set of match-grade dies, I did nothing. Of course, we were also using a post front sight. Was the occasional bad shot me, the rifle, the load or just an archaic sighting system?

Transitioning to optics has caused me to reconsider how and what I do in my reloading process: That, and having some extra time on my hands to experiment.

A little (or a lot) of time spent with a neck turning tool, a primer-pocket uniformer and a flash-hole reamer will quickly show you how consistent brass is by manufacturer and even by individual lot. That exercise also makes the prices charged for high-quality brass seem ridiculously cheap. That doesn’t mean that I advocate neck-turning or other uniforming practices, nor do I advocate spending scandalous amounts of money on long-range brass. However, our sport is about consistency. The consistency of your brass is a matter of choice, whether you choose to simply segregate cases by weight (cheap option), neck turn (labor intensive) or open your wallet a little wider for premium brass.

High Power service rifle AR15 reloading 600 yard Danny Arnold powder kernels

Weighing Charges vs. Throwing with Powder Measure
To measure or weigh? For a long time, I used a powder measure to throw all of my 600-yard loads. The powder I was using metered well, and the results downrange didn’t justify the extra time spent with a scale. That was in the day of iron sights though. Nowadays, I’m throwing my charges and trickling up to the desired weight as measured on a scale that weighs to a 100th of a grain.

To quantify the difference between individually weighing each charge versus throwing charges with a powder measure, I weighed six kernels of powder that I trickled into the pan and then dumped them into the hopper. Going through that process 10 times, I came up with an average weight of .08 grains for six kernels. Next, I threw 50 charges for weighing using my powder measure. If I felt the measure hanging up as it cut kernels, I put the charge back into the hopper without weighing it.

High Power service rifle AR15 reloading 600 yard Danny Arnold powder kernels
That’s six kernels of powder sitting in the pan — average weight .08 grains.

Those 50 smoothly-thrown charges varied .26 grains from lowest to highest, with the majority varying no more than .16 grains from highest to lowest. If the desired weight was exactly in the middle, at worst you’d be .13 grains (9-10 kernels) low or high, with the majority being off no more than .08 grains (6 kernels) above or below the desired charge weight. Is that enough to send a shot outside the 2-MOA 10-Ring? Probably not.

Has more consistent brass and weighing charges to one-hundredth (0.01) of a grain added up to higher scores? Honestly, this question is hard to answer. Looking at the results on paper at 200 yards, using a powder that meters well combined with a consistent touch on the loading lever doesn’t appear measurably different than meticulously weighing each and every powder charge. Looking back over my 600-yard plots however, I can see a trend toward a group that is closer to X-Ring height.

Since the bullseye is widest at the center, shooting groups that are the height of the X-ring gives you more room for error when the wind is blowing. That can translate into higher 600-yard scores.

How You Load Your Ammunition vs. How You Load Your Rifle
The loading/chambering cycle of the AR-15 is, in a word, violent. You have a relatively heavy bolt and carrier assembly under power of a stout buffer spring slamming forward to chamber each round of ammunition. By design, those rounds were supposed to be held securely by the magazine feed lips until the bolt stripped them off the follower. Obviously, due to their overall length, 600-yard loads can’t be chambered that way. Although the barrel extension is funnel-shaped, it’s also got a lot of “teeth” ringing the inside of it (see below).

High Power service rifle AR15 reloading 600 yard Danny Arnold powder kernels

Whether you’re using a standard magazine or a single-round loading device (SLED), dropping a round in the loading port and releasing the bolt is an act of faith in that you’re trusting the bullet to arrive in the chamber undamaged.

Ask yourself, how many times have you seen someone drop a round on the follower, press the bolt release and watch as the bolt jammed on a cockeyed round? If that happens once every 100 tries, how many times did the bolt close on a scratched, dented, or misaligned bullet? Could that be the cause of the occasional errant shot?

My technique is to drop each round on top of the SLED and then push it slightly forward with my finger, partially chambering it before releasing the bolt. Admittedly, some people may be unable to do this due to body configuration or left-handedness, but why go to all the trouble of loading “perfect” ammunition and then damage it on the way into the chamber?

Now that we’ve covered bullets, brass, and assorted errata we can move on to discussing loads for 600 Yards…

High Power service rifle AR15 reloading 600 yard Danny Arnold powder kernels highpower target
The NRA Highpower 600-yard target has a 6-inch (1 MOA) X-Ring, and a 12-inch (2 MOA) 10-Ring.

Load Development for 600 Yards

Finding a load for 600 yards is a lot like finding a load for short range. Once I decide on a bullet, powder, primer, velocity range and a measured guesstimate of seating depth, I load 10 rounds of each test load, increasing in 0.2 (2/10) grain increments. I test them from the prone position at 200 yards. Ideally, I want to see two loads that are 0.2 (2/10) of a grain apart that shoot almost identical groups. The load that I choose will fall in between the two best shooting loads that I tested. If the first load is XX.2 grains and the second is XX.4 grains, my chosen load will be XX.3 grains.

Why develop loads in 0.2-grain (tenths) increments if I have a scale that measures in 0.01-grain (hundredths) increments? Or, why not test in 0.1-grain increments?

For me, working in 0.2-grain increments gets me to the results quicker. Also, there is a difference between accuracy and consistency in this scenario. Developing loads in 0.2-grain increments gets me to an accurate load. Producing that load using a scale that accurately measures to .01-grain insures a consistent load, assuming that I do my part.

Once I’ve settled on a load, it’s time to play with seating depth, if I choose to. If I’m lucky and the groups are acceptable as-is, I won’t do anything. If I think there’s room for improvement, I’ll experiment a little. Depending on the bullet, changing the seating depth by a couple of thousandths one way or the other may change the group size. During this phase of testing, it’s a good idea to chamber a round and see if the entire round will then extract. If you leave a bullet stuck in the throat, your rounds are too long. Finding that out at a match can ruin an otherwise good day.

High Power service rifle AR15 reloading 600 yard Danny Arnold powder kernels
Danny Arnold shooting his AR15 Service Rifle, standing position at 2021 CMP Eastern Games.

Another thing to keep in mind is that your barrel is not static. Every round fired has an effect on the throat, vaporizing and scouring away metal until the distance the bullet travels before meeting the rifling measurably increases. If you have chosen a bullet that shoots best when close to the lands, you’ll need to periodically re-measure and possibly change your bullet seating depth to maintain that optimal relationship.

The Elephant in the Room — User Skill Level

There’s really not a delicate way to put this, so I won’t try. There’s little point in spending time and effort developing a load that shoots into half-MOA off the bench if you’re only capable of shooting 2 MOA using a sling right now.

That doesn’t mean that there’s no hope. On the contrary, it just means that your time and effort is better spent practicing with some good short-range ammunition on reduced targets at a 100 or 200-yard range. At that distance, wind is not a factor and your technique can be improved more quickly so you’re in a position to benefit from that ½ MOA ammunition.

About Team CMP
CMP has created a Highpower Team with top competitors. Team CMP competes at several events throughout the year and most importantly, helps to teach Highpower Clinics at CMP Competition Events. Learn from Team CMP at Camp Perry during the Advanced Highpower Clinic, scheduled this year for July 30 through August 1, 2021. Visit the Highpower Clinic Web Page for more information.

The Civilian Marksmanship Program is a federally-chartered 501(c)(3) non-profit corporation. It is dedicated to firearm safety and marksmanship training and to the promotion of marksmanship competition for citizens of the United States. For more information about the CMP and its programs, visit www.TheCMP.org.

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June 29th, 2023

Excellent, Informative Cartridge Diagrams — Download for FREE

Winchester centerfire rimfire pistol shotshell ammo ammunition cartridge diagram illustration

Winchester’s new “Introduction to Ammunition — Ammo 101” is a four-part series including custom illustrations and information for four major ammunition categories: rifle, pistol, rimfire, and shotshell. The Ammo 101 series provides a detailed overview of centerfire rifle, centerfire pistol, rimfire, and shotshell ammunition, showcasing ammunition construction, components, calibers, and common usage. The Ammo 101 resource is free to download from Winchesters.mediaassets.com. Or, simply click one or more diagrams below. Each image will launch a large PDF which you can print or download.

TIP: Click Each Image for Full-Screen Printable PDF

Shown below are the first four ammunition information sheets prepared by Winchester. These show all the key components of cartridges and shotshells, and explain the functions. These diagrams are useful for training, and for persons getting started in reloading.

Ammo 101 Centerfire Rifle Cartridge Diagram (click for PDF)

Winchester centerfire ammo ammunition cartridge diagram illustration

Ammo 101 Rimfire Cartridge Diagram (click for printable PDF)

Winchester centerfire ammo ammunition cartridge diagram illustration

Ammo 101 Pistol Cartridge Diagram (click for printable PDF)

Winchester centerfire ammo ammunition cartridge diagram illustration

Ammo101 Shotshell Diagram (click for printable PDF)

Winchester centerfire ammo ammunition cartridge diagram illustration


CLICK HERE for ALL FOUR Diagrams in SINGLE LARGE PDF »

About the Ammo 101 Series
The FREE Ammo 101 resources can help instructors nationwide who introduce new entrants to the shooting sports and hunting. Instructors can incorporate these resources into their training presentations, use them as handouts, or have them printed locally.

“The basics of ammunition… is what we want to deliver with the Ammo 101 series,” said Matt Campbell, Winchester V.P. of Sales & Marketing. “With millions of people across the United States starting their journey in the shooting sports as new firearm owners, providing easy-to-understand information on ammunition types is one way we can help educate our customers.”

Permalink Bullets, Brass, Ammo, Tech Tip No Comments »