Instead of using the standard .223 Remington or 5.56x45mm NATO round, you have many options for an AR-15. Dozens of cartridge variants have been tried in AR-15s. Some of the most noteworthy and popular alternative chamberings for AR-15s are:
20 Practical — This is simply the .223 Rem necked down to .204 caliber. Requires new barrel. Same bolt, same magazines. Best bang for the buck. .224 Valkyrie — A necked-down version of the 6.8 SPC, the .224 Valkyrie was introduced by Federal a few seasons back. It has better ballistics than the .223 Remington, if used with a suitable barrel. 6mm ARC — Relatively new cartridge that works well for varminting, self-defense, tactical competitions, and deer hunting. Good selection of bullets and factory-loaded ammunition. 6.5 Grendel — Accurate and proven across the course, the 6.5 Grendel requires a new barrel, bolt, and magazines. Most use the 6.5 Grendel for competitive shooting and/or hunting. .300 Blackout — Moderately expensive, the .300 Blackout requires a barrel change. This is used for home defense, and hunting. WARNING — with some bullets this round can be chambered in a .223 Rem barrel, with disastrous consequences. .458 SOCOM — Pretty expensive, requires new barrel and bolt. The .458 SOCOM round is typically used for hunting though it was originally designed for Close Quarters Battle (CQB).
Of these six options, our favorite is the 20 Practical, followed by the 6mm ARC and 6.5 Grendel. The 20 Practical is a great varminting round. Check out our featured 20 Practical AR Rifle Report. This 20 Practical cartridge is highly effective on small varmints, and has shown outstanding accuracy in AR-platform rifles crafted by Robert Whitley.
20 Practical — High-Velocity, Affordable Alternative
The 20 Practical is simply a .223 Remington necked down to .204 caliber. This efficient little cartridge can launch 32-grainers at over 4200 fps, with impressive results on P-Dogs. This makes the 20 Practical a great choice for an AR-based varmint rifle.
20 Practical Ultimate Varminter
A decade ago, as a “proof-of-concept”, AccurateShooter.com created a 20 Practical AR15 Ultimate Varminter with a custom 20-caliber upper from Robert Whitley of AR-X Enterprises, LLC. That project rifle was ultra-accurate — every 5-shot group out of the gun was less than the size of a dime. That gun was auctioned off, but Robert Whitley continues to produce custom 20 Practical AR15 uppers. (The 20 Practical cartridge is simply the .223 Rem necked down to 20 caliber — you can use standard .223 brass and load with standard .223 Rem dies. Just swap in a smaller expander and use smaller neck bushings.)
6mm ARC — Popular New SAAMI Cartridge Promoted by Hornady
In June 2020, Hornady introduced the 6mm ARC, a new SAAMI cartridge optimized for AR-platform rifles*. The new 6mm ARC is basically a 6.5 Grendel necked down to 6mm, with the shoulder moved back around .030″. That pushed-back shoulder does reduce case capacity (and velocity), but we assume Hornady did that to create a shorter, proprietary chamber so people could not simply neck-down Lapua 6.5 Grendel brass, as has been done for years with Robert Whitley’s outstanding 6mm AR wildcat.
What Is the 6mm ARC Cartridge? The 6mm ARC cartridge is a modern SAAMI-spec cartridge based on the 6.5 Grendel case necked down for 6mm bullets, with the shoulder moved back 0.030. Yes it is designed to run in AR15-platform rifles. You’ll need a new barrel, bolt, and mags. If you already have an AR chambered in 6.5 Grendel, the ONLY thing you need to change is the barrel. Everything else — bolt, magazines, gas system – is compatible with 6mm ARC.
▶ Official SAAMI Cartridge (not wildcat)
▶ Fits standard AR15-platform rifles
▶ Fits Short/Mini action bolt rifles
▶ Efficient short, fat case design
▶ 30-degree case shoulder
What Do I Need To Shoot the 6mm ARC?
Faxon and Ballistic Advantage are already producing barrels, with more manufacturers sure to follow. All the other required components are already on the market for 6.5 Grendel rifles. Aero Precision already offers complete 6mm ARC uppers.
If you’re converting a standard 5.56×45 mm (.223 Rem) AR15 upper to shoot 6mm ARC, you’ll need a 6mm barrel, a Type II 6.5 Grendel bolt carrier group, and new magazines. Some folks have suggested standard AR mags will work, but trust us, you want the magazines that have been designed for 6.5 Grendel. All the hardware you need is currently available at Brownells.
While 6-6.5 Grendel shooters are known to run stout pressures, the new 6mm ARC cartridge has a relatively moderate Maximum Average Pressure (MAP) rating of 52,000 psi according to the official SAAMI specifications. For a variety of reasons, is wise to keep pressures in a semi-auto rifle moderate. Don’t chase the velocities you might get in a bolt-action gun.
The 6.5 Grendel — Accurate, Plus Good for Hunters
The 6.5 Grendel round is one of the most accurate cartridges for the AR-15 platform. The 6.5 Grendel round offers a larger-diameter, .264-caliber (6.5mm) bullet running at good velocities. This provides ample energy for smaller game and deer. The 6.5 Grendel is often used for hunting deer up to 300 yards.
History of the 6.5 Grendel Cartridge
The 6.5 Grendel originated as a 6mm PPC necked up to 6.5 mm. After Alexander Arms relinquished the “6.5 Grendel” Trademark, the 6.5 Grendel was standardized as an official SAAMI cartridge. It has become popular with target shooters and hunters alike because it is accurate, efficient, and offers modest recoil. Good for small to medium game, the 6.5 Grendel has been offered in lightweight hunting rifles, such as the Howa 1500 Mini Action.
.224 Valkyrie Cartridge — Impressive with Heavy .22-Cal Bullets
The new .224 Valkyrie was introduced in 2019 as a Hot Rod cartridge that will work in AR15s. Basically a 6.8 SPC necked down to .22 caliber, the Valkyrie has a shorter case than the .223 Remington (and 5.56×45 NATO). This allows you to load the longest, heaviest .224-caliber bullets and still feed reliably from an AR15-type magazine. Designed to rival the .22 Nosler while still running well in ARs, the .224 Valkyrie offers excellent long-range performance when loaded with modern, high-BC bullets. We expect some bolt-action PRS shooters might adopt the .224 Valkyrie. Why? Reduced recoil. With the 90gr SMK, the .224 Valkyrie offers ballistics similar to the 6.5 Creedmoor but with significantly less felt recoil. It can also be a viable alternative to a .22-250 for varminters using an AR platform.
Our friend Gavin Gear of UltimateReloader.com found a superbly accurate load with Berger 80.5gr bullets. Watch this video to learn more:
Sierra Bullets has published extensive load data for the .224 Valkyrie. This covers over a dozen powder types — many more than the Hodgdon database. Sierra’s .224 Valkyrie load data covers projectiles from 50 grain all the way up to 95 grains. With the 90 to 95 grain bullets, the little Valkyrie can give 6mm match cartridges a real run for their money — offering similar ballistics with less recoil. When selecting a barrel for the long .224-cal bullets, specify a fast enough twist rate: “Sierra recommends a 1:6.5″-twist barrel for the #9290 22 cal 90 gr HPBT bullet. However, for cartridges like the Valkyrie, that can push them over 2650 fps muzzle velocity, a 1:7″-twist barrel will stabilize the bullet correctly.”
CLICK HEREto DOWNLOAD Complete Sierra .224 Valkyrie LOAD DATA.
.224 Valkyrie vs. .22-250 Remington
The Social Regressive explains: “There are two key reasons why the .224 Valkyrie is unique and desirable. First, it is specifically designed to fit the limitations of the AR-15 platform. It does so even when loaded with gigantic bullets, like the 90-grain SMK that Federal announced. The .22-250 Rem is too long and too fat to work in the AR-15 platform; it needs an AR-10 bolt and magazine.”
The .224 Valkyrie has been marketed as a low-recoil round that can stay supersonic to 1300 yards and beyond (with 90gr Sierra MatchKings). Here a Sniper’s Hide duo shots an AR-platform .224 Valkyrie at distances out to 1550+ yards. To be honest, the accuracy wasn’t that impressive. However this test confirms that the .224 Valkyrie does launch the long, heavy projectiles at high enough velocities to prove superior to the standard .223 Rem. Frank Galli (aka “Lowlight”) teams up with Brian Whalen of Colorado Precision Rifle at the Blue Steel Ranch in New Mexico.
The .300 Blackout — Risky Business
The .300 Blackout appeals to folks who want a .30-caliber defense round. This can be loaded at various velocities. Loaded at subsonic speeds and shot with a suppressor, the .300 BLK offers very low sound levels. 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.
The .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:
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 Remington.
2. Mark .223 Rem upper handguards with the caliber in bright paint.
2. Fit all your uppers with caliber-labeled ejection port covers.
4. Mark all .300 BLK Rounds with heavy black marker.
Most of us own a .223 Rem rifle. Now, thanks to our friends at Rifleshooter.com we can assess exactly how velocity changes with barrel length for this popular cartridge.
Rifleshooter.com performed an interesting test, cutting the barrel of a .223 Rem rifle from 26″ all the way down to 16.5″. The cuts were made in one-inch intervals with a rotary saw. At each cut length, velocity was measured with a Magnetospeed chronograph. To make the test even more interesting, four different types of .223 Rem/5.56 ammo were chron’d at each barrel length. The Rifleshooter.com team that conducts these tests has a full-service gun shop, 782 Custom Gunworks — visit 782guns.com.
Test Barrel Lost 25.34 FPS Per Inch (.223 Rem Chambering)
How much velocity do you think was lost, on average, for each 1″ reduction in barrel length? The answer may surprise you. The average speed loss of the four types of .223/5.56 ammo, with a 9.5″ shortening of barrel length, was 240.75 fps total (from start to finish). That works out to an average loss of 25.34 fps per inch.
5.56/.223 Barrel Cut-Down Speed Test 26″ to 16.5″
Start FPS at 26″
End FPS at 16.5″
Total Loss
Average Loss Per Inch
UMC .223 55gr
3182*
2968
214
22.5 FPS
Federal M193 55gr
3431
3187
244
25.7 FPS
Win m855 62gr
3280
2992
288
30.3 FPS
Blk Hills .223 68gr
2849
2632
217
22.8 FPS
*There may have been an error. The 25″ velocity was higher at 3221 fps.
Rifleshooter.com observed: “Cutting the barrel from 26″ to 16.5″ resulted in a velocity reduction of 214 ft/sec with the UMC 223 55-grain cartridge, 244 ft/sec with the Federal M-193 cartridge, 288 ft/sec with the Winchester M855 cartridge and 217 ft/sec with the Back Hills 223 68-grain match cartridge.”
How the Test Was Done
The testers described their procedure as follows: “Ballistic data was gathered using a Magnetospeed barrel-mounted ballistic chronograph. At each barrel length, the rifle was fired from a front rest with rear bags, with five rounds of each type of ammunition. Average velocity and standard deviation were logged for each round. Once data was gathered for each cartridge at a given barrel length, the rifle was cleared and the bolt was removed. The barrel was cut off using a cold saw. The test protocol was repeated for the next length. Temperature was 45.7° F.”
See More Barrel Cut-Down Tests on Rifleshooter.com
Rifleshooter.com has performed barrel cut-down tests for many other calibers/chamberings including 6mm Creedmoor, .308 Winchester, and .338 Lapua Magnum. See these test results at Rifleshooter.com.
Much Different Results with 6mmBR and a Longer Barrel
The results from Rifleshooter.com’s .223/5.56 test are quite different than the results we recorded some years ago with a barrel chambered for the 6mmBR cartridge. When we cut our 6mmBR barrel down from 33″ to 28″ we only lost about 8 FPS per inch. Obviously this is a different cartridge type, but also our 6mmBR barrel end length was longer than Rifleshooter.com’s .223 Rem start length. Velocity loss may be more extreme with shorter barrel lengths. And, of course, different cartridge types and powder/bullet combinations will yield different results.
TEN Shots in 0.303″ (0.289 MOA) at 100 Yards
Look at that target showing TEN shots at 100 yards, with eight (8) shots in the main cluster at the top. The ten-shot group measures .303″ (0.289 MOA), as calculated with OnTarget Software. Not bad for a handgun — a very nice bolt-action XP-100 pistol! What do you think, can your best-shooting rifle match the 10-shot accuracy of this XP-100 pistol?
Report by Boyd Allen
This story goes back a few seasons… this remarkable XP-100 pistol belongs to Dan Lutke, a Bay Area benchrest shooter who publishes the results for the Visalia matches to the competitors and the NBRSA. He has been an enthusiastic competitor for an number of years, at various ranges, notably Visalia and Sacramento. The action is a Remington XP-100, to which a Kelbly 2 oz. trigger has been fitted. On top is an old Japanese-made Tasco 36X scope (these were actually pretty darn good). The Hart barrel (a cast-off from Dan’s Unlimited rail gun) was shortened and re-chambered for the 6x45mm, a wildcat made by necking-up the .223 Remington parent case. The custom stock/chassis was CNC-machined by Joe Updike from 6061 Billet Aluminum to fit the XP-100 action and mount a target-style AR grip with bottom hand rest. The gun was bedded and assembled by Mel Iwatsubu. In his XP-100 pistol, Dan shoots 65gr custom boat-tails with Benchmark powder.
This diagram shows the most common 6x45mm wildcat, which is a necked-up version of the .223 Remington parent cartridge. NOTE: The dimensions for Dan Lutke’s benchrest version of this cartridge may be slightly different.
ACAD drawing by Peter Gnanapragasam CC by SA 3.0, via Wikimedia Commons. Title Added.
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)
Ammo 101 Rimfire Cartridge Diagram (click for printable PDF)
Ammo 101 Pistol Cartridge Diagram (click for printable PDF)
Ammo101 Shotshell Diagram (click for printable 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.”
The U.S. Army Marksmanship Unit regularly published a reloading “how-to” article on the USAMU Facebook page. One excellent “Handloading Hump Day” post covered preparation of once-fired 5.56x45mm brass. This article, the first in a 3-part series, has many useful tips. If you shoot a rifle chambered in .223 Rem or 5.56x45mm, this article is worth reading. You can obtain once-fired Lake City 5.56x45mm brass for less than half the cost of premium .223 Rem brass.
This week, Handloading Hump-Day will answer a special request from several competitive shooters who asked about procedures for morphing once-fired GI 5.56mm brass into accurate match brass for NRA High Power Rifle use. The USAMU has used virgin Lake City (LC) 5.56 brass to win National Championships and set National Records for many years. In this 3-part series, we’ll share techniques proven to wring match-winning accuracy from combat-grade brass.
GI brass has an excellent attribute, worth noting — it is virtually indestructible. Due to its NATO-spec hardness, the primer pockets last much longer than most commercial brass when using loads at appropriate pressures.
Preparing Once-Fired GI 5.56 Brass for Reloading (Part 1 of 3)
Assuming our readers will be getting brass once-fired as received from surplus dealers, the following steps can help process the low-cost raw material into reliably accurate components.
1. Clean the Brass
First, clean the brass of any dirt/mud/debris, if applicable. Depending on the brass’s condition, washing it in a soap solution followed by a thorough rinsing may help. [This step also extends the life of the tumbling media.] Approaches range from low-tech, using gallon jugs 1/2 full of water/dish soap plus brass and shaking vigorously, to more high-tech, expensive and time-consuming methods.
2. Wet-Tumbling Options (Be Sure to Dry the Brass)
When applying the final cleaning/polish, some use tumblers with liquid cleaning media and stainless steel pins for a brilliant shine inside and out, while others take the traditional vibratory tumbler/ground media approach. Degree of case shine is purely personal preference, but the key issue is simple cleanliness to avoid scratching ones’ dies.
If a liquid cleaner is used, be SURE to dry the cases thoroughly to preclude corrosion inside. One method is to dump the wet brass into an old pillow case, then tilt it left/right so the cases re-orient themselves while shifting from corner to corner. Several repetitions, pausing at each corner until water stops draining, will remove most water. They can then be left to air-dry on a towel, or can be dried in a warm (150° F-200° F max) oven for a few minutes to speed evaporation.
Shown below are Lake City cases after cleaning with Stainless Media (STM). Note: STM Case cleaning was done by a third party, not the USAMU, which does not endorse any particular cleaning method.
NOTE: The USAMU Handloading (HL) Shop does not RE-load fired 5.56 brass. We use virgin LC brass with our chosen primer already staked in place. However, our staff has extensive personal experience reloading GI brass for competition, which will supplement the Shop’s customary steps. In handloading, as in life, there are many ways to accomplish any given task. Our suggestions are note presented as the “only way,” by any means. Time for loading/practicing is always at a premium. Readers who have more efficient, alternative methods that maintain top accuracy are invited to share them here.
3. Inspect Every Case
Once dry, inspect each case for significant deformation (i.e., someone stepped on it), damaged mouths/necks and case head/rim damage. Some rifles’ ejectors actually dig small chunks of brass out of the case head — obviously, not ideal for precision shooting. Similarly, some extractors can bend the case rims so badly that distortion is visible when spinning them in one’s fingers. These can be used for plinking, but our match brass should have straight, undamaged rims.
Dented case mouths are common, and these can easily be rounded using a conical, tapered tool, [such as a .223 expander mandrel. A dummy 7.62 or .30-06 cartridge with a FMJ spitzer can also work.] If most of your brass is of one headstamp, this is a good time to cull out any odd cases.
4. Check the Primers Before Decapping
Your clean, dry and inspected brass is now ready for full-length sizing, decapping and re-priming. Historically, primer crimps on GI brass have caused some head-scratching (and vile language) among handloaders. Our next installment will detail efficient, easy and practical methods to remove primer crimp, plus other useful handloading tips. Until next week, Good Shooting!
Accuracy Potential of Mil-Surp 5.56×45 Brass
So, how accurate can previously-fired GI surplus brass be in a good National Match AR-15? Well, here’s a data point from many years ago that might be of interest. A High Power shooter who wrote for the late Precision Shooting magazine took a Bill Wylde-built AR match rifle to a registered Benchrest match. He had no difficulty obtaining consistent 0.5-0.6 MOA accuracy at 200 yards using LC brass and a generic “practice” load that was not tuned to his rifle.
Do you plan to use factory ammo in your hunting rifles? Perhaps you buy bulk centerfire ammo for your AR15s or varmint rifles. And you’ll certainly consider using factory ammo in all your rimfire guns. Then this book can definitely benefit you.
If you ever shoot factory ammo, you should consider getting Ammo & Ballistics 6. This resource lists over 2,600 different loads for 200+ cartridge types from .17 Mach 2 up to .700 Nitro Express, including the most popular centerfire and rimfire cartridges (both rifle and handgun). In this updated-for-2020 Sixth Edition, there are over 3,000 tables covering virtually every caliber and every load for all commercially-loaded hunting ammunition sold in the USA. Tables include velocity, energy, wind drift, bullet drop, and ballistic coefficients up to 1,000 yards.
Ammo & Ballistics 6 helps you select ammo for a hunt — quickly compare the velocity and knock-down power of various commercial ammo. This book can also help you choose a caliber/chambering for your next hunting rig.
Verified Book Purchaser Reviews
“Outstanding reference guide for shooters and ballistic enthusiasts alike. Has data on velocity, energy delivered, Taylor KO index, windage and elevation on numerous loadings for hundreds of [cartridge types]. Each cartridge has all dimensions labeled (i.e rim, case length, neck, etc.), and has an informative description of the cartridges history/relevance.” — S. Step, 2017
“Great heaps of data! This volume has pages and pages of new data for .22 LR like the hot Velocitor, and also on the .22 WMR from 30 grains up into the 50s. Most importantly there is lots of range data, drop, windage, kinetic energy, etc. — Terrific reference guide….” — E. Svanoe
Ammo & Ballistics 6 contains data and illustrations on virtually every sporting cartridge sold in the USA. This latest edition covers 200-plus cartridge types from .17 Mach 2 up to .700 Nitro Express.
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.
The .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:
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.
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
If you want to use an AR-platform rifle in the varmint fields, consider getting a 20-caliber barrel chambered for the efficient, low-recoil 20 Practical cartridge. The 20 Practical is simply a .223 Remington necked down to 20 caliber. The parent .223 Rem cartridge of course works great in an AR, but the 20 Practical offers some notable advantages for high-volume varmint shooters. The 20 Practical delivers very high velocity with very low recoil while still providing outstanding accuracy. The 20 Practical is great option for folks who favor “fast and light” — smaller, lower-mass bullets traveling at very high velocities. This little cartridge can launch 40-grainers at over 3900 fps, and 32-grainers even faster. This makes the 20 Practical a great choice for an AR-based varmint rifle.
20 Practical Ultimate Varminter
A decade ago, as a “proof-of-concept”, AccurateShooter.com created a 20 Practical AR15 Ultimate Varminter with a custom 20-caliber upper from Robert Whitley of AR-X Enterprises, LLC. That project rifle was ultra-accurate — every 5-shot group out of the gun was less than the size of a dime. That gun was auctioned off, but Robert Whitley continues to produce custom 20 Practical AR15 uppers. (The 20 Practical cartridge is simply the .223 Rem necked down to 20 caliber — you can use standard .223 brass and load with standard.223 Rem dies. Just swap in a smaller expander and use smaller neck bushings.)
Robert learned that the accuracy of the first 20 Practical AR15 was no fluke. After building six (6) more 20 Practical uppers, he tested them for accuracy and they all shot great. These uppers feature DPMS low-pro receivers with side-charging handles. They are fitted with PacNor 1:11″ twist, 3-groove stainless barrels.
Robert reports: “We have been making more 20 Practical AR15 uppers and I have to say I am astounded by the accuracy of these things. For shooting little tiny groups out of an AR15 with bullets going 3500+ fps, it’s hard to beat the 20 Practical. Today I test-fired six more uppers, all with 11-twist barrels. Three of the uppers had 24″ barrels, two had 20″ barrels, and one had an 18″ barrel (we call it ‘Stubby’).
In four of these uppers I shot re-sized Winchester brass using 25.3 grains of WC844 powder with Berger 40gr BTHP bullets loaded at 2.225″ OAL (about .015″ off the lands). WC844 is inexpensive military surplus powder that is nearly identical to H335. I tried three different primers and the choice did not seem to matter (CCI BR4, Rem 7 1/2s and Win Small Rifle — the old silver ones). All these four uppers shot great.”
Below is an animated GIF with targets from uppers #6, 10, and 11. All groups are mag-fed, 5-shot groups shot at 100 yards using a front rest and rear bag.
Targets Shot with Three Different 20 Practical AR Uppers
For more INFO visit www.6mmAR.com, or email: rcw3 [at] erols.com.
20 Practical Shooters Explain Why They Love this Little Cartridge
A current thread in our Shooters’ Forum focuses on favorite variants of the .223 Rem cartridge. The thread asks: “What is your favorite and most versatile round that you have made from a .223 Rem parent case?” Many cartridges were named, but the wildcat cartridge cited most often was the 20 Practical. Here are some comments by Forum members, who explain the appeal of this great little 20-caliber cartridge:
“The 20 Practical is just a hoot to shoot. Outstanding precision, minimal recoil, easy case forming and inexpensive to shoot. What’s not to like? It’s a great way to introduce kids to centerfire, too.” — JLT
“The 20 Practical for me. Never had as much fun shooting a rifle as I did with the 20 Practical. Also, [it is] the easiest wildcat to form. Just get cases, a couple of bushings to get the right neck tension, and you are shooting.” — NMKid
“Favorite .223 Rem Wildcat? The 20 Practical hands down for me. I have two of them built on Savage actions right now. One has a 20″ BHW barrel and the other has a 26″ Criterion. It is my go-to caliber for shooting up a Prairie Dog town and the ones I have are insanely accurate. Here are some typical 100- and 200-yard groups with my 20 Practicals.” — IA_Shooter
“My favorite was and is the 20 Practical. No fire-forming, no neck-turning, and with the increased BC of the 20 Cal bullets, it’s hard to wipe the smile off your face in a prairie dog town[.]” — Region Rat
“20 Practical and the [original] .223 Rem are my favorites. Accurate, cheap to shoot. The 20 Prac allows you to see your hits and it’s fast.” — Alguapo
“20 Tactical or 20 Practical. Both very easy to reload and/or form from .223 brass. And they are accurate, reach out on varmints at surprising ranges.” — Bill K
Smart Tips on Forming 20 Practical Cases
Varmint ace Warren B, aka “Fireball” in our Forum, explains how to form 20 Practical Cases. “Forming 20 Practical cases is very easy and no fire-forming is required. Start with any good quality .223 Rem brass. One can simply run the case into your bushing die with the appropriate bushing and call it done. I however like to make it a little more involved by doing the neck reduction in steps. I find that taking steps doesn’t overwork the brass as much as one step does. Also, if you resize the neck in too large of a step, sometimes, depending on the neck thickness, the neck will not be dimensionally what you would expect when finished. This is especially important towards the last step when one is getting close to the final required neck diameter.
For my cases the first thing I did was to run them into an old RCBS .223 Rem full length die with the decapping assembly removed. This will take care of any dented necks on the raw cases and bring the necks down to around 0.243″. Since all standard full-length dies oversize the necks way too much, starting with a .223 FL die actually reduces the neck diameter quite a bit–and obviates the need to buy an extra bushing for the first step. I then use my Redding Type-S die with two bushing sizes to get down to where I need to be. In other words, I start with the FL sizer, then move to a Type-S with a 0.233″ bushing and finish with a 0.228″ bushing. Notice how, as I get to the final step, I use progressively smaller increments in size between the reductions.” (Note: Depending on your brass your final bushing size may be different.)
20 Practical vs. 20 Tactical
Varminter Kevin Weaver, who shoots both the 20 Practical and 20 Tactical, states that: “Both the 20 Tactical and the 20 Practical are fine .20 caliber cartridges. However, my favorite would be the 20 Practical. The 20 Practical gives the SAME performance as the 20 Tactical without fire-forming, or having to buy expensive forming dies.
So with the 20 Practical you do less work, you shell out a lot less money, yet you give up nothing in performance. What’s not to like? To create 20 Practical cases, just buy a .223 Rem Redding Type “S” Bushing Die set with a .230 or .228 bushing and have fun with this great little cartridge.
The 20 Practical and the 20 Tactical are almost identical cartridges. There are only slight differences in case outside diameter, shoulder angle, and case body length. Neck length on the 20 Tactical is a bit longer, but there is still plenty of neck on the 20 Practical to grip the popular bullets, such as the 32gr V-Max.”
This week’s featured firearm belongs to John “SnakeEye” Seibel, founder of the VarmintsForFun website. In recent years, John has become a “true believer” in the little 20-Caliber cartridges. He says this light-recoiling 20 PPC, Rampro-actioned pistol is perfect for a quick shot on a critter, taken from the front seat of his truck. John tells us: “A long-range pistol is an ideal truck gun in my opinion. It stows in a small area and doesn’t take up the room a rifle does. Just keep ear protection near by at all times! I’ve taken varmints as far as 400+ yards with this 20 PPC pistol, so why would you need a rifle?”
Perspectives on Pistols for the Varmint Hunter
by John Seibel
I decided to try my hand at shooting varmints with a pistol one day when I grew tired of wrestling a rifle around in the truck for a quick shot. Many times when traveling around on the farm you’ll spy a groundhog or fox that usually isn’t more than 200 yards away. A single-shot pistol like the Thompson Contender could fit the bill. With its compact length, around 20 inches, a long-barrel pistol can lay on the truck’s passenger seat for easy access. I usually keep my two leather brick-style sandbags laying beside the console and seat. I have a box made from hard rubber that I lay across the top of the door. I then lay the two bags on top. This makes a nice platform to rest the pistol’s forearm. I like to use a forearm that is at least two inches wide. That lets the gun lay steady—almost like you are shooting from a bench rest. For the shooting hand, I prefer a pistol grip with finger grooves and a slight overhang or flare for the web of your hand.
As for optics, I tried long-eye-relief pistol scopes but they lacked the magnification you need for long-range target shooting or varminting. Those pistol scopes have really long eye-relief because they are designed to work with the pistol held at arm’s length. When shooting at the bench or from a truck that’s not what you want. By the time you find the target and get your eye in the exact location, the varmint has moved on or died of old age! After much fiddling around with pistol-type scopes, I finally decided to use rifle scopes on my long-range pistols. The minimum I use is a 4.5-14×40. Eye relief on a Leupold 4.5-14x40mm is about 3.5 inches at 4.5 power. Field of view is better with rifle scopes too and it’s easier to acquire your target. For this type of shooting a light-recoiling caliber is essential or you will have scope-eye bad! I currently have three long-range pistols and use them to shoot 17M4, 20 PPC, 22 BR, and .223 Rem. The featured gun may be the most accurate of my pistols, and your editor thinks it’s the most handsome of the three.
The Rampro Pistol Project — Working with John Illum
A couple of years ago I called John Illum of Rampro about building the ultimate long-range pistol. It just so happens that John was a big time long-range pistol shooter. I told him that I wanted a gun that didn’t recoil badly and wouldn’t torque when fired. As I am a quadriplegic, with no grip in my hands, the gun had to handle well under recoil so I didn’t drop it. Recoil had to be straight back–no twisting.
Well Illum listened to me and came up with a gun that performs just the way I wanted. Illum suggested a rear grip stock of his own design. It has a 2.25″ wide forearm and a rear grip with a slight palm swell that fits your hand perfectly. Another nice feature is the finger grips. It has an extended overhang or “beavertail” that fits comfortably in the web of your hand. Of course it had to be walnut! I chose Rampro’s STP small action with a PPC bolt. His bolt uses a Sako-type extractor. The action is a single-shot. Being right-handed, I chose a right bolt, left port configuration. This works really well in a pistol. You can load with your left hand and see the round laying in the action–that’s what you want in a pistol without a safety.
Gun Specifications John Illum’s Rampro actions are chrome-moly steel. Commonly you’d see them blued, but I had him put a brushed nickel finish on the action and rings. From a few feet away it looks like stainless. The trigger is Illum’s own design set at 8 ounces, and there’s no creep that I can detect. The action has Remington barrel threads and will accept Remington type triggers. One neat thing is that the action was milled with an integral recoil lug (much like the current Surgeon Action). And the bolt is milled all in one piece–no soldered-on handles. My only gripe with this bolt handle is that it could be a tad longer, but it still is manageable for a single-shot. You’ll also note how slick and streamlined the scope rings are. Illum made those as well. His rings mount to the action via two screws from the inside of the ring, a very elegant set-up for sure. (I currently have a 6.5-20x40mm Nikon scope on this gun. If I had to do this project over again the only thing I would change would be installing a 30mm scope because I like ‘em!).
The barrel is a PacNor Super-Match heavy taper with flutes milled by John Illum, who did all the gunsmithing on this pistol. Twist rate is 1 in 12 inches, with an 11° crown, polished to a mirror finish. The barrel was bead-blasted on the exterior to cut glare. I had Illum cut a 20 PPC minimum-spec chamber, with a .237″ neck. That way I don’t have to turn necks on the Lapua Brass (220 Russian necked down to .204). This is a varmint gun–there’s no need for turned necks. [Editor’s Note: Rampro is no longer in business. However, John tells us “I haven’t had any problems with the action so far. If I did, most competent gunsmiths could fix them easily.”]
Handgun Handling Tips
If you want to shoot a long-range pistol but have never have shot this kind of gun before, try to find a mentor — someone with a gun like this who can school you a bit in the correct technique. The first thing you notice is that you have no comb or cheek piece to help align your head and neck. And getting used to the optics takes some practice. Most people fit a pistol-type (long eye-relief) scope, but these can be awkward to use, and somewhat frustrating at first — the field of view is very restricted. Move your head very slightly and you can lose the sight picture completely. You can solve that problem by using a standard rifle scope, but that will put your head very close to the eye-piece — just three to four inches. With that arrangement, if you don’t hold the gun correctly … POW instant scope-eye!
Now once you get the hang of shooting a long-range pistol you will find it can be just as accurate as a rifle. But there is a trick to shooting them. Shooting a long-range pistol is a whole new world — you need to hold it just right. If you don’t let the gun roll back a little (i.e. if you grip too hard) you will get vertical stringing. I hold my hand against the back of the grip to guide the gun but let it almost free recoil. Looking at how compact the pistol is, you might think “Hey, this would make an ideal ‘walking-around’ varminter.” Well, that’s not really the case. For real precision shooting a solid benchrest type set-up is a must. You can attach a bipod to a long-range pistol, but you would need a flat surface. A fence-post top would work pretty well without a bipod if you carry a small light bag. Overall though, this type of pistol works best as a sandbag gun. For a walking-around gun, you’d be happier with a rifle I think.
Load Development and Accuracy
When I built this gun, Hornady had just released the 32gr V-Max (see footnote), a good match for my barrel’s 1:12″ twist. I choose the 20 PPC because of the very good Lapua brass (220 Russian parent case). I figured teaming Lapua brass with the little .204 bullet would offer excellent accuracy combined with very low recoil. My expectations were fulfilled. The brass proved to be excellent and the PacNor loved the little V-Max pills.
I tried quite a few different loads and most powders that I tried worked very well. These included: H322, Benchmark, AA 2460, and Reloader 7. Amazingly, with just 14″ of barrel, all of these powders delivered impressive velocities–ranging from 3914 to 4074 fps. I settled on 48 Harrell’s clicks of Accurate Arms (AA) 2460, which drives the 32gr V-Maxs to 3995 fps.
With AA 2460 the gun will shoot in the low 3s at 100 yards consistently — as long as I steer the gun right, which takes some practice. I think groups in the low 0.3″ range is excellent for a non-benchrest factory bullet. Despite having no buttstock to grab, recoil on my 20 PPC pistol is very minimal — it just rocks back into your hand. The main problem is to keep the scope from smacking you, since I used a rifle scope with short eye-relief. Muzzle flash and noise are tolerable but DO NOT shoot one of these without good ear protection. Your ears are very close to the muzzle.
I also have a 20 PPC rifle built on a BAT action with a Richard’s #008 laminated stock cut down in size. That gun’s 1:9″-twist Lilja barrel lets me shoot the Berger 50gr LTB bullets. In the wind, these perform quite a bit better than the 32s. My two favorite loads for the 50 grainers are: a) 26.0gr VV N135, CCI 450 primers, 3615 fps; and b) 27.3gr Hodgdon Varget, CCI 450s, 3595 fps. The BAT 20 PPC also shoots really well with the 40gr V-Max, pushed by N135 and Fed 205M primers.
Pistol Action Legal Issues
One important thing to remember if you build a pistol is to make sure the receiver came from the factory as a pistol and was titled as a pistol. Rifle actions are illegal to use as a pistol. Yes, that’s a nonsensical law, but it’s still on the books. You can use factory pistol actions such as the XP 100.
If you want a new custom action such as a BAT (my favorite), you can order it as a pistol action and when you get it, register it as a pistol. Note, in some states there may be additional fees, waiting periods, or restrictions for pistol actions (as opposed to rifle actions). Check your local laws before ordering the action.
Future Trends in Varmint Hunting — Plenty of Twenties
I think these sub-caliber rounds, both 20s and the 17s, are the future of recreational varminting, at least out to medium distances. The Twenties offer low recoil, excellent accuracy, and components keep getting better and better. The bullet-makers are finally making high-quality bullets in appropriate weights. Compared to something like a 22-250, I’ve noticed that my 20 PPC rifle has a lot less noise, a plus when you want to be quiet around other people and varmints.
The flat trajectory is another big advantage in the field. With the 20 PPC, zeroed at 100 yards, I can pretty much hold dead center and get hits out to 300 yards or so without touching the scope to add elevation. [Editor: The same is true with the 20 Practical cartridge, basically a .223 Rem necked down to .20 Caliber. It has proven very accurate and easy to tune.]
The 20-Caliber cartridges we have now, in particular the 20 PPC and 20 BR, are very well-refined. You don’t have to do a lot of tuning or tinkering to have a very accurate, effective varmint-slayer. In fact, if I could dream up a signature “20 VFF” (Varmints For Fun) cartridge it would basically be the 20 PPC. In truth, nearly any of the popular 17- or 20-Caliber cartridges will perform well if you start with top-quality brass. The sub-calibers have less recoil and burn less powder, and there are very good components for most varmint and target-shooting applications. To me it seems that these small calibers work so well because of good components, low recoil, and efficient cartridge designs (particularly in the VarTarg and PPC cases).
WARNING: For your own safety, ALWAYS reduce all starting charges by 10% and work up carefully! Ambient temperature changes, powder lot variations, and differences in barrel friction can result in significantly increased pressures.
20 PPC LOAD MAP
Bullet GR
Maker
Powder
Charge
Primer
Case
Velocity fps
Barrel Twist
Comments
32
Hornady V-Max
H322
27.6
Rem 7½
Lapua
4000
Lilja 1:12
WarrenB Form Load
32
Hornady V-Max
AA 2460
29.5
Rem 7½
Lapua
3995
PacNor 1:12
SnakeEye Pistol Load
32
Hornady V-Max
H4198
25.1
CCI BR4
Lapua
4222
PacNor 1:12
A. Boyechko Load
39
Sierra BlitzKing
H322
26.0
Rem 7½
Lapua
3700
Lilja 1:12
WarrenB Load
39
Sierra BlitzKing
VV N540
28.8
CCI BR4
SAKO
4064
PacNor 1:12
D.Moore, Low 2s
40
Hornady V-Max
VV N135
27.8
Fed 205m
Lapua
3950
Lilja 1:9
SnakeEye Load
50
Berger LTB
VV N135
26.0
CCI 450
Lapua
3615
Lilja 1:9
SnakeEye Load
50
Berger LTB
Varget
27.3
CCI 450
Lapua
3595
Lilja 1:9
SnakeEye Load
Footnote: When first manufactured, the small Hornady 20-Caliber V-Max bullet was actually 33 grains, not 32 grains as sold currently. I still have some of the 33-grainers. I’ve observed no functional difference between the 33s and the current 32-grainers.
Here is one of Bill Reid’s 6mmBR (6BR) rigs. Like his Sako 6 PPC, this is exceptionally accurate.
AccurateShooter Forum member Bill White (aka “CT10Ring”) is a New Yorker who relocated to Idaho in his senior years. From his Idaho home, Bill enjoys long-range target shooting. But his favorite gun pastime is varmint hunting in nearby states — the Dakotas, Montana, and Wyoming. Every year he loads up his truck and hits the road, often doing a grand circle route, visiting prairie dog havens in multiple states.
Bill has a large rifle collection, most of which see duty in the varmint fields of Montana, North Dakota, South Dakota, and Wyoming. Here are his key “take-aways” for his eight favorite varmint chamberings: .204 Ruger, .223 Rem, .22-250, .22 BR, .22-243, 6 PPC, 6mmBR, and 6-6.5×47 Lapua (aka 6×47).
Eight Great Varmint Cartridge Types — .204, .224, .243 Calibers
.204 Ruger — This delivers great velocity with the little .20-caliber bullets, with mild recoil. The .204 Ruger easily reaches out to 400 yards, but heavier winds do move the tiny bullet around. Tremendous splat factor under 250 yards. I use Sierra 39gr bullets with IMR 8208 XBR in a Sako 75. Even now, .204 Ruger ammo is relatively easy to find.
.223 Remington — Probably the most popular centerfire rifle round in the USA, the .223 Rem offers inexpensive brass, and is a great choice for AR-15 owners. If you run short on ammo, you can find it nearly everywhere. I often bring one AR-15 and one .223 Rem bolt gun on varmint safaris. My Rem 700 5R 1:9″-twist barrel likes 53gr V-Max bullets.
.22 BR — My .22 BR is my first choice for most prairie dog missions. Accuracy is superb with necked-down 6mmBR Lapua brass — quarter-MOA and blazing fast. With the right twist rate, this chambering can shoot anything from 40gr FB bullets to 80gr VLDs. Load development is easy. Below is my .22 BR ammo for another varmint trip. I use 55gr Sierra BlitzKings with Varget in my 1:12″-twist Shilen-barreled rifle. 60gr Bergers are very accurate with a fairly flat trajectory for useful distances.
.22-250 Rem — A classic varmint cartridge, the .22-250 with 50gr V-Maxs delivers spectacular hits. If three P-Dogs happen to be lined up, I’ve witnessed one .22-250 shot take ‘em all out with a triple hit. I currently have five .22-250-chambered rifles: 3 Sako 75s, one Rem 700, and a single shot Nesika that shoots tiny groups. I favor the very deadly Berger 52gr Varmint HP. Making a custom .22-250? With a 1:8″-twist barrel you can use the full weight range of .22-cal bullets, while spinning the lighter bullets fast for “red mist” effect. Remember this cartridge can be a barrel burner. Don’t shoot too many rounds too quickly.
.22-243 Win — This wildcat is even more potent than the .22-250, delivering devastating results on P-Dogs. Run a .243 Win case slowly through a full-length .22-243 die, with plenty of lube to form the brass. I start with Lapua .243 Win brass. There can be some issues necking-down the brass. Watch for donuts forming at the neck-shoulder junction. I bought my .22-243 rifle not sure how it would perform. But now I love shooting it. My .22-243 delivers half-MOA groups with 41.0 grains RL-22 and Hornady 75gr Amax bullets. With those 75-grainers, it’s great in the wind and good to 600 yards easily.
6 PPC — You may consider the 6 PPC a benchrest competition cartridge only, requiring fire-forming. However I have an original Sako 75 single-shot 6 PPC rifle that I load with Sako-headstamp 6 PPC brass (see below) so no fire-forming is required. This Sako 75 came with a test target that measured 0.113″! With my 6 PPC Sako, I found that 58gr V-Maxs, pushed by Vihtavuori N133, are potent out to 300 yards. [Editor’s NOTE: As the Sako brass is no longer available, new 6 PPC shooters will need to fire-form their brass, or try to find Norma 6 PPC brass.]
6mmBR — The 6mmBR Norma (6BR) offers a nearly unbeatable combination of accuracy, efficiency, and tunability. With the 6BR and a fast twist barrel, you can shoot everything from 40gr flat-base bullets to the latest 105-110gr match bullets. I load Lapua brass, Vihtavuori N135, and Hornady 58, 65, and 75gr bullets for my Krieger 1:14″-twist HV barrel. While this cartridge is capable of long-range accuracy, I usually limit my 6BR shots to 350-400 yards.
6-6.5×47 Lapua — I have a nice 6-6.5×47 Lapua varmint rifle, with Surgeon action and Manners stock. I Cerakoted the barreled action and then bedded the action. Shown below is 6-6.5×47 ammo I loaded for testing. Note how I separated different bullets and powder loads into multiple, labeled bags. Hodgdon H4350 is a great choice for this cartridge — 39 grains H4350 with 105gr Amax was the winner here, but 88gr Bergers also shot well. This cartridge has tremendous “critter dismantling” abilities out to 600-700 yards.
Six Tips for Novice Long Range Varmint Hunters
1. Take twice as much ammo you think you may need. The fields could be particularly rich, or, because of wind or other variables, you may have far more misses than expected.
2. When possible, set up with the wind at your back (or, alternatively, directly ahead). This will minimize the effect of cross-winds. Set up a stake with a ribbon to show wind direction.
3. Bring at least two rifles. Ideally one would be a low-recoil rifle with cheaper components for the closer shots. Then bring a rifle with higher-BC bullets for longer shots where wind is a bigger factor.
4. Check the weather before you head out. Prairie dogs like sunshine and calm conditions. If a cloudy, very blustery day is predicted, considering staying in town and cleaning the rifles.
5. Bring plenty of water on a trip. An adult male should be drinking at least 64 ounces of water (or other liquid) every day — more if it’s very hot or you are sweating a lot.
6. Preferably always hunt with a companion. If you do go out solo, have a Garmin inReach SatComm/GPS for emergencies if there is no cell coverage in your location.