Do you know how gun primers are made — how the explosive elements are applied into those tiny cups? Find out by watching this video filmed at a Federal ammunition factory. It starts out with empty primer cups loaded, 1000 at a time, into trays using vibration (0:05 time-mark). While much of the process is automated, there is still a significant role played by production workers who apply a green, paste-like charging compound to the inside of hundreds of primer cups.
At the 0:17-second time-mark you can see the factory worker “charging” the primers with the priming compound. After the cups are filled, then the plate of cups “mates up with a plate of anvils” (0:40 time-mark). Then the primers are unloaded from trays and inspected.
Primer “Mysteries and Misconceptions” Article
There is an excellent article about primers on the Shooting Times website. This authoritative Shooting Times article explains the fine points of primer design and construction. The author reveals some little-known facts about primers and corrects common misconceptions. Here are some highlights:
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.
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) $29.99 on Amazon
Fits: 380 Auto, 9mm Luger, 38 Super, 40 S&W, 45 ACP, 38/357, 44 Spl/Mag, and 45 Colt
Aluminum MSR Black Color Ammo Checker (#7833003) $54.20 on Amazon (third party, MidwayUSA)
Fits: .223 Rem/5.56, 6.5 Grendel, 6.8 SPC, 300 AAC Blackout, 7.62×39, 450 Bushmaster, 458 SOCOM, and 50 Beowulf.
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.
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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. Palmetto State Armory — AR15 Lower Receiver, $49.99
⏺ Grab AR Lower while you can if anti-2A Dems win election
With Election Day tomorrow 11/5/2024, and the threat of aggressive anti-gun executive orders if Kamala Harris gets elected, you want to get that AR15 build started while you still can. If you need an AR lower, here’s a great deal. Palmetto State Armory (PSA) now has stripped AR15 lowers for just $49.99. With this lower as the core, you can build up your AR for any discipline you choose: 3-Gun rifle, service rifle competition, varmint rifle, or even “race gun” for the PRS Gas Gun Series. These PSA lowers are forged using 7075-T6 Aluminum and have a durable, mil-spec anodized hardcoat finish.
2. Savage — November Savage Precision Rifle Rebate, Save $200
⏺ Save $200 on Savage chassis rifle for PRS/NRL matches
Here’s a great way to save $200 on a rifle for PRS/NRL precision shooting competitions. With the purchase of a Savage m110 Elite Precision, m110 Precision, or Impulse Elite Precision rifle you qualify for a $200 mail-in rebate from Savage. CLICK HERE for rebate info page. NOTE: This offer is valid for purchases made from November 1-30, 2024. Purchase these Savage rifles from a leading retailer such as Sportsman’s Warehouse. For hunters, there is also a $100 Rebate on purchase of a Savage Impulse hunting rifle.
⏺ Get quality slide-mount Red Dot Optic with Walther pistol
Now through 12/31/24, if you buy a Walther PDP handgun you get a FREE C&H Precision Red Dot Optic valued at $338. There are multiple Walther PDP pistol models, starting at $599.99 retail. This Free Red Dot offer applies to the PDP Compact, Full-Size, F-Series, PRO, MATCH, and Steel Frame models. The C&H optic will fit with no Adapter Plate required. You get the free optic with a PDP purchase from Walther dealers, such as Palmetto State Armory, which has virtually all popular PDP pistol models in stock. View redemption instructions at WaltherArms.com/FreeOptic.
4. Amazon — Garmin Xero C1 Chrono with Accessories, $609.95
⏺ Superb Radar Chrono plus battery and accesssories
The Garmin Xero C1 Pro Chronograph is the most popular radar Chrono on the market now for good reason. It is ultra-reliable, very accurate, easy to set up, and very compact. The price for the unit by itself is $599.99 for all legit sellers, but Amazon is offering a nice deal. For ten bucks more you can get a Garmin Xero C1 Combo Kit which includes external battery, charging accessories, extra cables, car charging socket, and cleaning cloth. If you want for a Garmin C1 Pro, this kit is worth the $10 extra. Plus Amazon Prime members get FREE 2-day shipping. Another option to consider is the nice Xero C1 Pro Carry Case.
6. EuroOptic — Tikka Rifle Close-Out Sale — Save Hundreds
⏺ Tikka makes great hunting rifles now offered at major savings
With this Close-Out Sale at EuroOptic.com,you can save $150-$200 on a quality Tikka T3x hunting rifles, starting at just $649.99. Multiple models are on sale including T3x Lite, T3x Lite Compact, T3x Lite Stainless, T3x Hunter, and T3x RoughNeck. Both right-hand and Left-hand versions are offered. The Hunter models feature a handsome wood stock. These rifles can deliver sub-MOA accuracy with good hand-loads.
7. Natchez — CCI, Federal, Remington Ammo Sale
⏺ Very good deals on pistol ammo and rimfire ammo
Need 9mm or .380 ACP pistol ammo? Could you use bargain .22 LR or .22 WMR for your rimfire guns? Then head over to Natchez which has a wide variety of pistol and rifle ammunition on sale. There’s a large selection of 9mm ammo, as low as 25 cents per round. You’ll also find bargain-priced bulk packs of .22 LR ammo from Federal and CCI. Act soon as some of these deals expire on Tuesday, November 5, 2024.
8. Amazon — Digital Trigger Pull Gauge, $17.99
⏺ Cool sub-$20 tool that works really well — great buy
The Pridefend Professional Digital Trigger Pull Gauge (#ad) offers great performance for a very low price. We’ve used this “smart” pull gauge with success on match rifle triggers. This gauge measures in 1 oz. increments from 0 to 12 pounds. The gauge display is easy to read and you can choose ounce, pound, or Kg units. Though it costs just $17.99, this digital gauge offers better consistency than many conventional spring-type gauges. Plus, when you do a sequence of multiple pull tests on one gun, the unit automatically calculates maximum, minimum, and average pull weights.
9. KYGUNCO — KONUS 1-8X Night Vision Binoculars, $99.99
Here’s a good night vision optics solution for hunters and outdoorsmen. These 1x-8x KONUS Konuspy-17 digital day/night binoculars are on sale for $99.99, a 17% savings. These offer 1920×1080 resolution with day/night video recording capability. The unit has nice finger controls, plus a tripod mount on the underside. Shipped with a carrying case, these come with A/V cable and USB cable for recharging. The Konuspy-17 binoculars provide the visual quality of high-end night optics at a fraction of the cost.
10. Amazon — Frankford Arsenal Depriming Tool, $39.99
⏺ Convenient tool — no press needed to deprime anywhere
Decapping fired brass can be tedious when using a reloading press and decapping die. Make things easier with the Frankford Arsenal Platinum Series Hand Deprimer Tool (#ad). You can deprime cases while watching TV. This handheld unit features an easily removable spent primer catch tube and an assisted-ejection case holder for easy removal of deprimed cases. The handle is spring-loaded to return the deprimer to the start position automatically.
As an Amazon affiliate, this site can earn revenues through sales commissions.
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More and more shooters are “wet-tumbling” their brass (in liquid) with reusable polishing media, rather than using dry media in a vibratory tumbler. The “wet-cleaning” method works best with a rotary tumbler fitted with a water-tight, horizontal drum to hold your brass, cleaning solution, and stainless, pin-type media. The rotary tumbler of choice has been the Thumler’s Tumbler Model B Heavy-Duty. That is a great, sturdy machine, but now you have a more affordable option.
Frankford Arsenal offers “Platinum Series” rotary tumblers designed to clean cartridge brass with liquid and stainless media. The watertight, polymer drum rides on four rollers which rotate the drum around its horizontal axis. Two filters are provided so you can quickly separate your brass and media. A built-in timer allows you to set tumbling sessions up to three hours. There is a large, 7-liter unit and a smaller, 3.3-liter tumbler. Frankford Arsenal says the big version will clean up to 1000 cases of .223 Rem brass. That’s impressive capacity.
Rotary Tumbler Sources Online
The Frankford Arsenal Platinum Series rotary tumblers are sold by major retailers including Grafs.com, Midsouth, MidwayUSA, and Amazon. It’s wise to shop multiple vendors to find the best current pricing.
Amazon often has very competitive pricing on the Frankford Arsenal Rotary Tumblers, both the big, high-capacity 7-liter unit ($179.97) and the smaller 3.3-liter tumbler ($84.99).
How to Wet-Clean Your Brass in a Rotary Tumbler
On our main Accurateshooter.com website, you’ll find a comprehensive review of the STM system for cleaning cartridge brass with stainless media. To clean brass with stainless media, start with five pounds of small stainless pins sold by StainlessTumblingMedia.com. Place these along with a gallon of water, a little liquid cleaner, and two pounds of cartridge brass in a rotary tumbler, and run the machine for one to four hours. After cleaning be sure to inspect all your primer holes. CLICK HERE for Brass Cleaning System Review.
Forum Member Tests STM System
Our reviewer, Forum member Jason Koplin, purchased the STM media and a new Thumler’s Tumbler. He then tested the STM cleaning procedure on his own brass, including some extremely dirty and tarnished “range pick-up” brass. Jason was thoroughly impressed with how well the STM process worked — as you can see from the “before and after” photos below. Brass which looked like it was ready for the scrap heap was restored to “like-new” appearance. The process works equally well on both rifle brass and pistol brass. Jason observed that one surprise benefit of the STM cleaning procedure is a big reduction in noise. Jason said the water-filled rotary tumbler was much quieter than his vibratory tumblers. One tip though — you should always inspect every cartridge carefully after wet-tumbling with stainless media. With large-flash-hole brass it is possible to have a pin stuck in a flash hole. This is rare, but it CAN happen.
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Widener’s Reloading & Shooting Supply has published a helpful introduction to reloading powders. Widener’s online Guide to Smokeless Powders shows the various types of powders, and explains how the differences in powder kernel/flake size and shape, and burn rate affect performance. We recommend you visit Widener’s website and read the Powder Guide in full.
Take a close look at these illustrations which show the key differences between the four main powder types: extruded (stick) powder, ball (spherical) powder, flattened ball powder, and flake powder.
Burn Rate Basics
Widener’s Guide to Smokeless Powders also has a useful discussion of Burn Rate (a confusing topic for many hand-loaders). Wideners explains: “While a gun powder explosion in the cartridge seems instantaneous, if you slow it down you will actually find that each powder has a different ‘burn rate’, or speed at which it ignites.” This video shows powders with two very different burn rates. Watch closely.
Different burn rates suit different cartridge types notes Widener’s: “In general a fast-burning powder is used for light bullets and low-speed pistols and shotguns. Medium-rate powders are used for magnum pistols, while high-velocity, large bore rifle cartridges will need slow powders[.]
It should be noted that burn rate does not have a standardized unit of measurement. In fact, burn rate is really only discussed in comparison to other powders; there is no universal yardstick. Specifics will change by cartridge and bullet types[.]”
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With our inflationary economy, ammo continues to go up in price every year. Smart shooters can benefit by price-shopping to get the best deals on factory-loaded ammunition, particularly for popular cartridge types such as .22 LR, 9x19mm (9mm Luger), .357 Mag, .223 Rem (5.56×45), and 6.5 Creedmoor. It this article we list 15 reliable online sources for factory-loaded ammo. You may want to bookmark this page so you can quickly scan and price-check multiple vendors. In addition, you can use a service such as AmmoSeek.com.
Why Should You Shop for Ammo Online?
By shopping online for ammo, you can save money, get a wider selection, and get bulk discounts. GunDeals.com explains: “Online purchases [can] save you a lot of money [and can] also save your time… one of the most important advantages is definitively the huge selection.” With online retailers you can quickly compare prices, and you will often get a discount on a large order (300 rounds or more) that is not available in local stores. Note, with some large vendors such as Cabela’s and Sportsman’s Warehouse you can order online then pick up in a local store.
Are There Restrictions on Online Ammo Purchasing?
In most (but not all) U.S. states is it legal to order ammunition online to be shipped to your residence. However, you MUST check your State and local laws and regulations. In some states and/or cities, it is ILLEGAL to purchase ammunition online for shipment across state lines with direct delivery. For example, in California, all ammo must be purchased from a licensed ammo dealer/vendor with a state background check (so much for the Second Amendment)*. Likewise Washington DC, and Hawaii do not allow online ammunition purchases. And there are restrictions in New York City. In Alaska there are multiple shipping regulations that impact ammo deliveries from online sales so many vendors do not ship to Alaska.
*In some instances ammo can be purchased online from an out-of-state seller who will then ship to an authorized, in-state California vendor who may transfer the ammo for a fee with background checks as required by CA law.
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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 $172.99 with three 25-rd mags.
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.”
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
“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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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.
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I have seen it time and time again, shooters on the line wrestling with their rifle trying to get the bolt closed while the wind is switching. They were too focused trying to get their bolt to close and getting their rifle settled back on the bags that they missed the wind switch. Bang… Eight! The straw that broke the camel’s back for me was at the 2017 Canadian Nationals. I was paired up with a young girl and she would try really hard to close the bolt on her rifle. The majority of the time she would get it to close, but often times she could not even get the round to chamber. She was focused on her rifle the entire time rather than on the conditions. When we completed our strings, she had five rounds that did not chamber our of 15! That is way too many!. I told her she needed to think about Full-length sizing with 0.002″ shoulder bump, or Controlled Full-length Sizing like I call it. I told her not to worry about losing accuracy. I told her that I full-length size all my rounds and asked if she noticed how smooth my bolt was and noticed my score. She said yes, they were both great!
Controlled Full-length Sizing Does NOT Harm Accuracy
I have found that Controlled Full-length Sizing does NOT hurt accuracy or shorten brass life. I find that I can focus much more on the conditions when I don’t have to think about chambering a round nor extracting it. It has become second nature. After firing, I keep my head welded to the stock, I open the bolt by placing my thumb on top of stock and rotating hand upwards. I reach in and retrieve spent case, place it back in ammo box, and pick up another loaded round and put in chamber. I verify conditions and when ready, I push the bolt in and close it with my index and middle finger.
With Controlled Full-length Sizing you “bump” the shoulder around .002″ for bolt guns.*
Whidden Full-Length Sizing Dies by AccurateShooter.com Editor
For proper full-length sizing, you want a quality die that’s a very good match to your chamber. For our project rifles we usually turn to Whidden Gunworks which offers both bushing and non-bushing FL dies. And if you want the hot new option, check out Whidden’s patent-pending, click-adjustable FL-sizing die. This gives instant, precise control over shoulder bump. It works great.
*With gas guns, such as the AR10, you may want to increase shoulder bump to .003″ or more. With some benchrest cartridges, .0015″ bump may prove optimal. But .002″ is a good starting point.
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Efficient cartridges make excellent use of their available powder and case/bore capacity. They yield good ballistic performance with relatively little recoil and throat erosion.
Cartridge Efficiency: A Primer (pun intended!)by USAMU Staff
The U.S. Army Marksmanship Unit (USAMU) published a series of reloading articles on its Facebook Page. In this article, the USAMU discusses cartridge case efficiency and its benefits. While this is oriented primarily toward NRA High Power Rifle and Long Range (1000-yard) competition, these factors also apply to medium/big game hunters. Assuming one’s rifle and ammunition are accurate, key considerations include ballistic performance (i.e., resistance to wind effects, plus trajectory), recoil, and throat erosion/barrel life.
Efficient cartridges make excellent use of their available powder and case/bore capacity. They yield good ballistic performance with relatively little recoil and throat erosion. A classic example in the author’s experience involved a featherweight 7x57mm hunting/silhouette rifle. When loaded to modern-rifle pressures, just 43-44 grains of powder pushed a 139gr bullet at 2900 fps from its 22” barrel. Recoil in this light rifle was mild; it was very easy to shoot well, and its performance was superb.
An acquaintance chose a “do everything” 7mm Remington Magnum for use on medium game at short ranges. A larger, heavier rifle, it used ~65 grains of powder to achieve ~3200 fps with similar bullets — from its 26″ barrel. Recoil was higher, and he was sensitive to it, which hampered his shooting ability.
Similarly efficient calibers include the 6mm BR [Norma], and others. Today’s highly-efficient calibers, such as 6mm BR and a host of newer developments might use 28-30 grains of powder to launch a 105-107gr match bullet at speeds approaching the .243 Winchester. The .243 Win needs 40-45 grain charges at the same velocity.
Champion-level Long Range shooters need every ballistic edge feasible. They compete at a level where 1″ more or less drift in a wind change could make the difference between winning and losing. Shooters recognized this early on — the then-new .300 H&H Magnum quickly supplanted the .30-06 at the Wimbledon winner’s circle in the early days.
The .300 Winchester Magnum became popular, but its 190-220gr bullets had their work cut out for them once the 6.5-284 and its streamlined 140-142gr bullets arrived on the scene. The 6.5-284 gives superb accuracy and wind performance with about half the recoil of the big .30 magnums – albeit it is a known barrel-burner.
Currently, the 7mm Remington Short Action Ultra-Magnum (aka 7mm RSAUM), is giving stellar accuracy with cutting-edge, ~180 grain bullets, powder charges in the mid-50 grain range and velocities about 2800+ fps in long barrels. Beyond pure efficiency, the RSAUM’s modern, “short and fat” design helps ensure fine accuracy relative to older, longer cartridge designs of similar performance.
Recent design advances are yielding bullets with here-to-fore unheard-of ballistic efficiency; depending on the cartridge, they can make or break ones decision. Ballistic coefficients (“BC” — a numerical expression of a bullet’s ballistic efficiency) are soaring to new heights, and there are many exciting new avenues to explore.
The ideal choice [involves a] balancing act between bullet BCs, case capacity, velocity, barrel life, and recoil. But, as with new-car decisions, choosing can be half the fun!
Factors to Consider When Evaluating Cartridges
For competitive shooters… pristine accuracy and ballistic performance in the wind are critical. Flat trajectory benefits the hunter who may shoot at long, unknown distances (nowadays, range-finders help). However, this is of much less importance to competitors firing at known distances.
Recoil is an issue, particularly when one fires long strings during competition, and/or multiple strings in a day. Its effects are cumulative; cartridges with medium/heavy recoil can lead to shooter fatigue, disturbance of the shooting position and lower scores.
For hunters, who may only fire a few shots a year, recoil that does not induce flinching during sight-in, practice and hunting is a deciding factor. Depending on their game and ranges, etc., they may accept more recoil than the high-volume High Power or Long Range competitor.
Likewise, throat erosion/barrel life is important to competitive shooters, who fire thousands of rounds in practice and matches, vs. the medium/big game hunter. A cartridge that performs well ballistically with great accuracy, has long barrel life and low recoil is the competitive shooter’s ideal. For the hunter, other factors may weigh more heavily.
Cartridge Efficiency and Energy — Another Perspective
Former Lapua staffer Kevin Thomas explains that efficiency can be evaluated in terms of energy:
“Cartridge efficiency is pretty straight forward — energy in vs. energy out. Most modern single-based propellants run around 178-215 ft/lbs of energy per grain. These figures give the energy potential that you’re loading into the rifle. The resulting kinetic energy transferred to the bullet will give you the efficiency of the round. Most cases operate at around 20-25% efficiency. This is just another way to evaluate the potential of a given cartridge. There’s a big difference between this and simply looking at max velocities produced by various cartridges.”
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On our main AccurateShooter.com site, you’ll find a good article by GS Arizona on the Basics of Neck Turning. If you’re new to the neck-turning game, or are just looking for good tips on improving your neck-turning procedures, you should read that article. Below we offer some highlights and photos from the article, but you’ll need to read the whole story to view all the illustrations and follow all the procedures step by step.
Why Should You Consider Neck Turning?
Let’s assume that your rifle doesn’t have a tight neck chamber that requires neck turning; if you have a tight neck chamber, of course, the answer to the question is “because you have to”. For the rest of us, and that includes the vast majority of Highpower shooters, neck turning isn’t a requirement, but it can be a useful way to bring your ammunition a small but meaningful step closer to that pot of gold at the end of the rainbow: perfection. I’m not talking about a theoretical improvement, but a real one, an improvement that lies in equalizing and optimizing the neck tension of your loaded rounds. Inconsistent neck tension is a real contributor to increased muzzle velocity variance which itself is a significant factor in increased elevation dispersion at long range. So there’s our basic reason for neck turning: to equalize and optimize neck tension in order to reduce elevation dispersion.
The Tools of the Trade
Here you see everything I use and a bit more. The press, a cordless screwdriver (always plugged in, turning is tough on the old battery), a couple of K&M neck turners (one set up for 6mm, the other for .30 caliber) an expander for each size, some Imperial lube, an old toothbrush or two to keep the cutter clean, a handle with a caseholder (for those emergencies when the screwdriver dies and there’s just one more case to go!), steel wool and a tubing micrometer finish the list of tools. Hey, I left the dial calipers out of the picture! They’re always handy, keep them around, but they are useless for measuring neck thickness, so don’t try. I usually use an Optivisor magnifier while I turn necks, very handy for a clear view of what’s happening on the neck.
Expanding the Neck
Put some lube on the inside of the case neck and run it into the expander. Really, this isn’t hard. I prefer to expand each case immediately before turning it as opposed to expanding all the cases and then turning them. Brass is somewhat springy and will tend to go back toward its original size; therefore, by expanding and turning immediately, you are more likely to have all cases fit the mandrel with the same degree of tightness and to get a more consistent depth of cut.
Cutter Adjustment for Cut Depth and Length
All the tools I’ve seen have pretty good adjustment instructions. The only thing they don’t tell you is that you should have five to ten spare cases to get it right initially. Anything of the right diameter will do while you learn, for instance, just use that cheap surplus .308 brass to do initial setup and save the precious .30-06 for when you know what you’re doing. Be patient and make your adjustments slowly; you’ll need to set the cutter for thickness as well as length of cut (just into the shoulder). The depth of cut (brass thickness) takes a bit of fiddling, the length of the cut is generally easy to set.
The Finished Product — A Perfectly Uniform Neck
If you read the whole article, and follow the procedures using quality tools, you should get very good results — with a little practice. To demonstrate, here’s an example of my finished, neck-turned brass. You’ll see there is a perfect, 0.0125″ thick neck. It’s very uniform around the circumference, usually I only see 1 or 2 ten-thousandths variance. Now, with the necks uniformed like this, we can select the bushing size that will give us our preferred neck tension and experiment with various levels of tension, secure in the knowledge that all of the cases will actually have the desired neck tension.
About the author — “GS Arizona” was the writing handle for German Salazar, a top-tier rifleman and gun writer. Sadly, German passed from a medical condition in 2022. German was instrumental in helping this website and our Forum get started, and we remember him as a very dear, valued friend.
German was a great individual, and a great asset to the sport. An attorney by trade, with an engineering background, German was one of the very best gun writers, who had high master shooting skills to match his writing abilities.
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