We are often asked “Can I get more velocity by switching primer types?” The answer is “maybe”. The important thing to know is that changing primer types can alter your load’s performance in many ways — velocity average, velocity variance (ES/SD), accuracy, and pressure. Because there are so many variables involved you can’t really predict whether one primer type is going to be better or worse than another. This will depend on your cartridge, your powder, your barrel, and even the mechanics of your firing pin system.
BE SAFE: Be cautious when changing primer types. Glen Zediker recommended decreasing your load ONE FULL GRAIN when changing to a different primer type, one that you haven’t used before.
Interestingly, however, a shooter on another forum did a test with his .308 Win semi-auto. Using Hodgdon Varget powder and Sierra 155gr MatchKing bullets, he found that Wolf Large Rifle primers gave slightly higher velocities than did CCI-BR2s. Interestingly, the amount of extra speed (provided by the Wolfs) increased as charge weight went up, though the middle value had the largest speed variance. The shooter observed: “The Wolf primers seemed to be obviously hotter and they had about the same or possibly better ES average.” See table:
Varget .308 load
45.5 grains
46.0 grains
46.5 grains
CCI BR2 Primers
2751 fps
2761 fps
2783 fps
Wolf LR Primers
2757 fps
2780 fps
2798 fps
Speed Delta
6 fps
19 fps
15 fps
You can’t extrapolate too much from the table above. This describes just one gun, one powder, and one bullet. Your Mileage May Vary (YMMV) as they say. However, this illustration does show that by substituting one component you may see significant changes. Provided it can be repeated in multiple chrono runs, an increase of 19 fps (with the 46.0 grain powder load) is meaningful. An extra 20 fps or so may yield a more optimal accuracy node or “sweet spot” that produces better groups. (Though faster is certainly NOT always better for accuracy — you have to test to find out.)
WARNING: When switching primers, you should exercise caution. More speed may be attractive, but you have to consider that the “speedier” primer choice may also produce more pressure. Therefore, you must carefully monitor pressure signs whenever changing ANY component in a load. In his books, the late Glen Zediker recommended decreasing your load ONE FULL GRAIN when changing to a different primer type, one that you haven’t used before.
Over the past 12 months, this article was one of the TOP 20 most-read Daily Bulletin features. We’re reprising it today for those who may have missed it the first time. The above diagram comes from a TiborasurasRex YouTube Video comparing G1 and G7 BC models. CLICK HERE to watch the video.
The better, up-to-date ballistics programs let you select either G1 or G7 Ballistic Coefficient (BC) values when calculating a trajectory. The ballistic coefficient (BC) of a body is a measure of its ability to overcome air resistance in flight. You’ve probably seen that G7 values are numerically lower than G1 values for the same bullet (typically). But that doesn’t mean you should select a G1 value simply because it is higher.
Some readers are not quite sure about the difference between G1 and G7 models. One forum member wrote us: “I went on the JBM Ballistics website to use the web-based Trajectory Calculator and when I got to the part that gives you a choice to choose between G1 and G7 BC, I was stumped. What determines how, or which one to use?”
The simple answer is the G1 value normally works better for shorter flat-based bullets, while the G7 value should work better for longer, boat-tailed bullets.
G1 vs. G7 Ballistic Coefficients — Which Is Right for You?
G1 and G7 refer both refer to aerodynamic drag models based on particular “standard projectile” shapes. The G1 shape looks like a flat-based bullet. The G7 shape is quite different, and better approximates the geometry of a modern long-range bullet. So, when choosing your drag model, G1 is preferable for flat-based bullets, while G7 is ordinarily a “better fit” for longer, boat-tailed bullets.
Drag Models — G7 is better than G1 for Long-Range Bullets
Many ballistics programs still offer only the default G1 drag model. Bryan Litz, author of Applied Ballistics for Long Range Shooting, believes the G7 standard is preferrable for long-range, low-drag bullets: “Part of the reason there is so much ‘slop’ in advertised BCs is because they’re referenced to the G1 standard which is very speed sensitive. The G7 standard is more appropriate for long range bullets. Here’s the results of my testing on two low-drag, long-range boat-tail bullets, so you can see how the G1 and G7 Ballistic coefficients compare:
G1 BCs, averaged between 1500 fps and 3000 fps:
Berger 180 VLD: 0.659 lb/in²
JLK 180: 0.645 lb/in²
The reason the BC for the JLK is less is mostly because the meplat was significantly larger on the particular lot that I tested (0.075″ vs 0.059″; see attached drawings).
For bullets like these, it’s much better to use the G7 standard. The following BCs are referenced to the G7 standard, and are constant for all speeds.
Many modern ballistics programs, including the free online JBM Ballistics Program, are able to use BCs referenced to G7 standards. When available, these BCs are more appropriate for long range bullets, according to Bryan.
[Editor’s NOTE: BCs are normally reported simply as an 0.XXX number. The lb/in² tag applies to all BCs, but is commonly left off for simplicity.]
This article is copyright 2023 AccurateShooter.com. No 3rd Party republication of this article is allowed without advance approval and payment of licensing fees.
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.
Among AccurateShooter.com’s most-visited web pages have been powder burn rate reference guides ranking powders from fastest to slowest. Here is a new, updated version of the Powder Burn Rate Table. Compiled by Hodgdon Powder Co., this Burn Rate Chart displays the relative burn rates of 176 different powders. Shown below is the latest table, released by Hodgdon in July 2024.
You’ll want to download this Powder Burn Rate Chart PDF. This 176-entry comparison table provides vital information for hand-loaders — with tested burn-rates. Note — this invaluable chart is not limited to Hodgdon and IMR propellants. This burn rate chart includes powders from eight major powder-makers: Accurate, Alliant, Hodgdon, IMR, Norma, Ramshot (Western), Vihtavuori, and Winchester.
This chart (July 2024 version) provides useful information for all hand-loaders. When doing load development, and testing one powder versus another, it’s generally wise to choose propellants that share the same relative burn rate, as least for starters.
NOTE: Hodgdon powders are red, IMR powders are yellow, Winchester powders are blue, Accurate powders are gray, and Ramshot powders are orange. Powders from Alliant, Norma, and Vihtavuori appear on the chart with white background. DOWNLOAD Burn Rate Chart HERE as PDF.
Hodgdon Powder Company (Hodgdon) offers a series of informative, “how-to” instructional videos through its online Reloading Data Center. These 3.5-minute videos present rifle, pistol, and shotshell reloading basics in an easy-to-understand, step-by-step format. These mobile-friendly, informative videos can also be viewed on a smart phone or tablet.
To watch the reloading videos go to the Reloading Data Center at hodgdon.com. Click to the right/left of the displayed video to switch between pistol, rifle, and shotgun videos. Or, for your convenience, we have embedded the Rifle and Pistol videos here. Just click to watch!
Click to Watch Hodgdon Rifle Reloading Video:
Click to Watch Hodgdon Pistol Reloading Video:
In addition to these videos, Hodgdon’s Reloading Data Center (RDC) provides a wealth of information on Hodgdon, IMR, Accurate, Winchester, and Ramshot propellants. Along with reliable load data, you’ll find explanations of reloading basics, safety procedures, plus answers to frequently asked questions (FAQ).
At the request of our readers, we provide select “Deals of the Week”. Every Sunday afternoon or Monday morning we offer our Best Bargain selections. Here are some of the best deals on firearms, hardware, reloading components, optics, and shooting accessories. Be aware that sale prices are subject to change, and once clearance inventory is sold, it’s gone for good. You snooze you lose.
NOTE: All listed products are for sale to persons 18 years of age or older. No products are intended for use by minors.
1. Midsouth — Athlon Rangecraft Vel Pro Chronograph, $399.99
⏺️ » impressive new compact radar chrono — competition for Garmin
The new Athlon Rangecraft Velocity Pro Radar Chronograph is an impressive and very affordable compact chrono, now $399.99 at Midsouth. This employs Doppler radar allowing ultra-accurate velocity readings. Since the unit isn’t triggered by a muzzle blast, it can work with suppressors, muzzle brakes, and other muzzle devices. The Rangecraft Vel Pro reads velocities between 65 FPS and 5000 FPS. So far field tests have shown that the Athlon Rangecraft chrono is very reliable and picks up all shots fired with all types of rifles and pistols (even airguns). However the listed velocities may be a few FPS different than a Magnetospeed or Labradar. Athlon also has a good Ballistics Lite App that works with this chrono — see video at 21:45 time-mark. The unit includes a compact tripod.
2. Natchez — Truglo Optics Sale, Save up to 34%
⏺️ » Major savings on Truglo scopes — good for hunters and AR shooters
Truglo optics (scopes, red dots), offer notable features and great value. Right now Truglo optics products are on sale at Natchez at crazy low prices. For example the Truglo 4-16x44m EMINUS16 scope with illuminated reticle and scope mount is now just $209.99 — $111.00 off the regular $321.00 price. And for AR shooters the 1-4x24mm OMNIA4 Tactical scope is discounted to $159.99 complete with rugged Aptus-M1 scope mount (with rings) — a $75 savings.
3. Creedmoor Sports — Peterson Brass Sale
⏺️ » Save on good, American-made cartridge brass
Quality loads demand quality brass. We’ve been impressed with American-made Peterson brass that has performed great for popular cartridge types including 6mm Dasher, 6XC, 6×47 Lapua, 6mm Creedmoor, 6.5 Creedmoor, .308 Win, .300 Norma Mag, .300 WinMag, .338 Lapua, .376 CheyTac and others. Peterson brass is very consistent and holds up well for multiple reload cycles. With the current Peterson sale, there are substantial discounts for: 6.5 Creedmoor, .260 Rem, 6.5 PRC, 7mm-08, 7mm RUM, 30 Nosler, .300 RUM, 33 Nosler, and .338 Lapua.
4. Amazon — VEVOR 50″ Rifle TSA-Compliant Hard Case, $96.38
⏺️ » Good waterproof hard case with wheels — great value
Protecting your firearms requires a good, tough transport case. The VEVOR 50″ Rifle Case (#ad) features three layers of protective foam, solid locking points, wheels, and a IP67 waterproof case. This VEVOR gun case meets TSA gun case requirements, making it a good choice for marksmen and hunters who travel by air. At just $96.38 (29% off) this is a great deal — much cheaper than other sturdy, wheeled rifle cases of similar size. This case is Amazon’s #1 Best Seller among rifle hard cases.
5. MidwayUSA — Umarex Air Rifle Sale
⏺️ » Air rifles offer affordable shooting for many disciplines
With centerfire and rimfire ammunition costs rising, more people are giving airguns a try. Air rifle shoppers should consider Umarex airguns. These start at well under $200 with the current Umarex Sale at MidwayUSA. For example, the Umarex Synergis Elite Air Rifle just $179.39 on sale, including 3-9x40mm scope. And the impressive Umarex Gauntlet SL22 PCP Air Rifle is now just $389.89, $60 off the regular price. The Umarex lineup includes a wide variety of airguns from $55 to $1100 — for fun shooting or high-level competition. NOTE: For air rifles no FFL is required for transfer in most states.
6. Midsouth — Rifle Basix Trigger Sale, Save 10%
⏺️ » Excellent Triggers for Remington, Howa, CZ, Savage — 10% OFF
Do you want to upgrade your rifle’s trigger but have a limited budget for the trigger replacement? Consider Rifle Basix Triggers. Offered for many rifle brands including Remington, Savage, Howa, and CZ, Rifle Basix triggers feature crisp breaks and lighter trigger pull weight. Enhanced triggers can translate to better accuracy (and shot consistency) at the range and in the field.
7. Amazon — Frankford Arsenal Universal Seating Die, $67.83
⏺️ » Great, versatile system for seating multiple caliber bullets
Are you tired of buying another expensive seating die every time you try a new cartridge type? With the unique Frankford Arsenal Universal Bullet Seating Die (#ad) you can have one die that loads multiple cartridge types. This clever bullet-seating system includes 3 different stems and 9 sleeves allowing you to seat .224 to .338-caliber bullets with this one multi-caliber tool. Forum members using this system have praised it. NOTE: the universal seating die comes with the .308-caliber sleeve pre-installed.
Barrel heat can shorten life and cause erratic testing results. One very good barrel-cooling system is Chuckwalla’s Competition barrel cooler (#ad). This low-profile cooler has a flow tube that fits right-hand bolt-action rifles from .223 REM to .300 WSM. (It can also run in even larger chambers but with a looser fit.) The Chuckwalla’s shape and orange color allows this cooler to serve as a chamber flag. This cooling fan includes a AA battery pack with 8-hour run time and a USB charging connection. NOTE: As the AA batteries are NOT included, we suggest using rechargeable AA batteries.
9. Amazon — Acoway Roll-up Shooting Mat, $17.99
⏺️ » Handy roll-up mat at super-low price — black or green
Most rifle shooters can use a good, simple shooting mat that can be easily rolled up and stored. The ACOWAY Roll-Up Shooting Mat (#ad) measures 76″ x 29″ and has a durable, double-layered Nylon outer fabric in Black or Green. This mat provides a protective barrier between you and the ground. The black mat is just $17.99 while the green version is $19.99, both great deals. The mat folds into a handy smaller size, held with attached straps and clips.
As an Amazon affiliate, this site can earn revenues through sales commissions.
Forum member F-Class John is an avid F-Class competitor and expert handloader. John reviews reloading hardware and shooting-related products for his popular F-Class John YouTube Channel, which now boasts 500+ videos. John also does important product testing for AccurateShooter.com. Through his YouTube channel, John has reviewed many of the latest and greatest reloading tools and accessories. For today’s Video Showcase, we selected eight F-Class John product reviews. Products tested include front rests, AMP Annealer, Flavio Fare triggers, AutoDod IDOD power neck-turner, Henderson and Giraud case trimmers, Zero turret press, 21st Century arbor press, and Accuracy One concentricity checker.
If you like these informative videos, consider joining F-Class John’s Patreon Channel for live video meetings, more in-depth videos, and detailed explanations. Join Patreon via Patreon.com/fclassjohn for full length videos, live chats, and more.
SEB NEO-X and Rodzilla Raptor Front Rests
This video covers two outstanding front joystick rests, the SEB Neo-X and the Rodzilla Raptor. Both of these rests work great for both benchrest and F-Class shooters, centerfire and rimfire. Build quality is outstanding for both rests. Tester F-Class John observes: “Both are great units and user preference will really dictate which to get. I own both and find they give me consistent target acquisition.” To learn more about these two excellent front rests, visit TheRodzilla.com and/or SEB Rests USA.
Flavio Fare Triggers Tested
The Flavio Fare triggers are some of the best on the market. These are offered for various action types including Remington clones and custom actions. CLICK HERE for a discussion of these triggers on our Forum. The Flavio Fare Veloce Hunting Trigger (with safety) adjusts from 5 to 25 ounces pull weight and retails for $439.95. The Flavio Fare Whisper 2.1 BenchRest Trigger (no safety) adjusts from 0.7 to 2.8 ounces, and costs $449.95. Reviewer F-Class John says these Flavio Fare triggers are “smooth, crisp, with a wide range of trigger pull weights … I love these things.”
Annealing Made Perfect AMP Mark II DB Annealer
This detailed 9.7 minute review outlines the features of the latest AMP electronic annealing machine, the AMP Mark II DB. This uses a computer control to deliver precise annealing times and temperatures with a profile for your specific lot and brand of brass. One user praised this new AMP machine: “The touch screen is much more intuitive than the old one.” Another stated: “If you want to anneal the best way possible this is it. Does a torch work? Sure it does. The AMP does it far better and far more consistently.” A buyer confirmed this sophisticated new AMP is fast and efficient: “Just got one, a few days ago and it’s so easy to use. Without even trying, I easily anneal eight rounds per minute”.
Bryan Blake, a very clever machinist and gunsmith, has created an ultra-precise and speedy neck-turning machine. Bryan, who runs Blake Machine, Blake Barrel, and F-Class Products has created a system that uses twin precision cutter tips to turn case necks inside and out quickly and efficiently, with superior precision. This advanced IDOD Neck Turning Machine holds cases securely in a precision-machined spindle attached to an electric motor. Twin blades move precisely during the cutting process, milling the necks inside and out. The turned necks come out perfect every time, with the shoulders trimmed exactly (with doughnut removed) as well.
Henderson vs. Giraud Case Powered Case Trimmers
After adding the impressive Henderson Gen 3 Powered Trimmer to his inventory of tools. F-Class John became is a Henderson fan. He likes the speed, precision, and repeatability of the $779.00 Henderson machine, which trims-to-length and chamfers the case mouth all in one pass. Unlike some other trimming tools, the Henderson indexes off the overall case length NOT the shoulder. The Giraud trimmer is a very different design which indexes off the case shoulder, but it is also very precise. When set up correctly, it can trim brass with amazing consistency. As long as you have fire-formed brass with consistent base-to-shoulder dimensions, you should get very consistent trim lengths.
Zero Turret Press with Whidden Sizing Die
The Zero Press from Area 419 is arguably the best turret press ever crafted. It offers unrivaled precision, along with the highest-capacity turret head with NINE die/tool stations. Milled from billet aluminum and stainless steel, this press moves with the help of 14 bearings. In this video, F-Class John shows how to use a Whidden Gunworks full-length sizing die on the Zero Press. And John has two other video reviews of the $1275 Zero Press: 1. Zero Press First Thoughts Video; 2. Loading on a Zero Press.
21st Century Hydro Press and Standard Arbor Press
John notes: “You can’t really talk about precision reloading without taking about inline dies and arbor presses. For my money there’s nothing better than the lineup from 21st Century Shooting. They offer the Hydro Seater which is hands-down the best manual seater out there as well as their standard arbor press which is great for taking on the road to push back bullets as needed.”
Concentricity Checking with Accuracy One Gauge
Every serious hand-loader needs a quality concentricity gauge. The Accuracy One Concentricity Gauge boasts a smart design that delivers precise, repeatable results. We like the unit’s easy adjustability and its ability to work in a variety of configurations. The Accuracy One Gauge measures internal and external neck runout of cartridge cases as well as seated bullet runout. It can also measure the runout of the ogive, bearing surface, and boat-tail of individual bullets. And it can even measure your primer pocket runout. Reviewer F-Class John notes: “I think this is the best concentricity tool on the market. Such a tool is a necessity for new loaders or those who are always setting up new dies.”
Put the same load in a variety of barrels (with the same length and chamberings) and you’ll see a wide variance in muzzle velocity. In fact, it’s not unusual to see up to 100 fps difference from one barrel to the next. We demonstrated this with a comparison test of Lapua factory ammo.
Chron Testing Lapua Factory Ammo
At our Southern California test range some years ago, we chronographed Lapua 105gr 6mmBR factory ammo in three different 8-twist barrels of similar length. The results were fascinating. Lapua specs this ammo at 2790 fps, based on Lapua’s testing with its own 26″ test barrel. We observed a speed variance of 67 fps based on tests with three aftermarket barrels.
Barrel Velocity Variance
Brand ‘S’ and Brand ‘PN’ were pre-fit barrels shot on Savage actions. Brand ‘K’ was fitted to a custom action. All test barrels were throated for the 100-108 grain bullets, though there may have been some slight variances in barrel freebore. With a COAL of 2.330″, the rounds were “jumping” to the rifling in all barrels.
Among the four barrels, Brand ‘PN’ was the fastest at 2824 fps average — 67 fps faster than the slowest barrel. Roughly 10 fps can be attributed to the slightly longer length (27″ vs. 26″), but otherwise this particular barrel was simply faster than the rest. (Click Here for results of 6mmBR Barrel Length Velocity Test).
IMPORTANT: Results Are Barrel-Specific, Not Brand-Specific
These tests demonstrate that the exact same load can perform very differently in different barrels. We aren’t publishing the barrel-makers’ names, because it would be wrong to assume that ‘Brand X’ is always going to be faster than ‘Brand Y’ based on test results from a single barrel. In fact, velocities can vary up to 100 fps with two identical-spec barrels from the SAME manufacturer. That’s right, you can have two 8-twist, 26″ barrels, with the same land-groove configuration and contour, from the same manufacturer, and one can be much faster than another.
Don’t Demand More Than Your Barrel Can Deliver
We often hear guys lament, “I don’t get it… how can you guys get 2900 fps with your 6BRs and I can only get 2840?” The answer may simply be that the barrel is slower than average. If you have a slow barrel, you can try using more powder, but there is a good chance it may never run as fast as an inherently fast barrel. You shouldn’t knock yourself out (and over-stress your brass) trying to duplicate the velocities someone else may be getting. You need to work within the limits of your barrel.
Factory Ammo Provides a Benchmark
If you have a .223 Rem, 6mmBR, .243 Win, 6.5×47 Lapua, 6.5 Creedmoor, 6.5×55, .308 Win, .30-06 Springfield, or .338 LM Rifle, we recommend you buy a box of Lapua factory-loaded ammo. This stuff will shoot great (typically around half-MOA), and it can give you a baseline to determine how your barrel stacks up speedwise. [Editor’s NOTE: The original test was conducted in 2008. The velocity of current-production Lapua factory ammo might be higher or lower, so your results may vary.]
When you complete a new 6mmBR rifle, it’s definitely smart to get a box of the factory ammo and chronograph it. That will immediately give you a good idea whether you have a slow, average, or fast barrel. Then you can set your velocity goals accordingly. For example, if the factory 6BR ammo runs about 2780-2790 fps in your gun, it has an average barrel. If it runs 2820+ in a 26″ barrel (or 2835 fps in a 28″), you’ve got a fast tube.
There is an excellent article about primers on the Shooting Times website. We strongly recommend you read Mysteries And Misconceptions Of The All-Important Primer, written by Allan Jones. Mr. Jones is a bona fide expert — he served as the manager of technical publications for CCI Ammunition and Speer Bullets and Jones authored three editions of the Speer Reloading Manual.
This authoritative Shooting Times article explains the fine points of primer design and construction. Jones also reveals some little-known facts about primers and he corrects common misconceptions. Here are some highlights from the article:
Size Matters
Useful Trivia — even though Small Rifle and Small Pistol primer pockets share the same depth specification, Large Rifle and Large Pistol primers do not. The standard pocket for a Large Pistol primer is somewhat shallower than its Large Rifle counterpart, specifically, 0.008 to 0.009 inch less.
Magnum Primers
There are two ways to make a Magnum primer — either use more of the standard chemical mix to provide a longer-burning flame or change the mix to one with more aggressive burn characteristics. Prior to 1989, CCI used the first option in Magnum Rifle primers. After that, we switched to a mix optimized for spherical propellants that produced a 24% increase in flame temperature and a 16% boost in gas volume.
Foiled Again
Most component primers have a little disk of paper between the anvil and the priming mix. It is called “foil paper” not because it’s made of foil but because it replaces the true metal foil used to seal early percussion caps. The reason this little disk exists is strictly a manufacturing convenience. Wet primer pellets are smaller than the inside diameter of the cup when inserted and must be compacted to achieve their proper diameter and height. Without the foil paper, the wet mix would stick to the compaction pins and jam up the assembly process.
Primer Functionality and Primer Types Compared
This video looks at a variety of primer types from multiple manufacturers, foreign and domestic. The video explains the basics of how primers function, and then explains the key characteristics of standard primers, magnum primers, and mil-spec primers (designed for semi-auto rifles).
Here’s a cool tool for your hand-loaders, particularly if you load large quantities of bulk ammo for a variety of firearms. Lyman’s handy Ammo Checkers check the diameters of reloaded rounds and factory ammo, so you can quickly confirm that your ammo fits a standard chamber. Just drop your loaded rounds in the Ammo Checker, and if the round fits into the gauge, it will fit in the gun’s chamber.
Lyman Ammo Checkers are multi-caliber — each orange block checks six or eight different cartridge types, with each caliber/cartridge name engraved on the gauge. Ammo Checkers are machined to SAAMI minimum chamber dimensions from solid blocks of 6061 T6 aluminum. Ammo Checkers are available in three versions covering most common handgun and rifle calibers:
Handgun Ammo Checker (#7833000) $32.99 on Amazon
Fits: 380 Auto, 9mm Luger, 38 Super, 40 S&W, 45 ACP, 38/357, 44 Spl/Mag, and 45 Colt
Why Use a Case Gauge?
We find that case gauges like the Lyman Ammo Checker are particularly useful for handgun reloaders using progressive presses. The chambers of many popular semi-auto pistols are partly unsupported. This allows the case to swell in the bottom quarter. The case may not be sized adequately by your sizing die, which can lead to misfeeds or malfunctions.
Additionally, if you have loaded a large quantity of ammo for a semi-auto rifle such as an AR15, it’s not a bad idea to check your cartridges before you load them into your magazines. All you need is one mis-sized round to cause a stoppage. That will ruin your day if you are competing in a Service Rifle match or 3-Gun event.
The better, up-to-date ballistics programs let you select either G1 or G7 Ballistic Coefficient (BC) values when calculating a trajectory. The ballistic coefficient (BC) of a body is a measure of its ability to overcome air resistance in flight. You’ve probably seen that G7 values are numerically lower than G1 values for the same bullet (typically). But that doesn’t mean you should select a G1 value simply because it is higher.
Drag Models — G7 is better than G1 for Long-Range Bullets
Popular Cartridge Types Profiled
Barrel Velocity Variance
