Right now the 2025 Southwest Nationals 1000-yard individual competition is underway at the Ben Avery range outside Phoenix. Along with the F-Class matches (for F-TR and F-Open), there is a “hard-hold” division with competitors shooting rifles with sling in prone position. At the SWN this sling division has two sub-classes: “A” for “Any Rifle, Any Sight” and “P” for Palma rifles. These Palma rifles must shoot with iron sights, and they are limited to two chamberings: .223 Remington (5.56×45) and .308 Winchester (7.62×51). These Palma rifles typically feature long barrels for enhanced velocity, and a sophisticated stock that offers multiple adjustments.
Palma rifle division shooter at the Southwest Nationals a few seasons back.
Today’s Saturday showcase we features six videos showing key features of modern Palma rifles. In addition, we offer insight into loading the .308 Win cartridge for long-range accuracy. Even with iron sights, modern top-tier Palma rifles are capable of shooting exceptional scores at 600 to 1000 yards.
About Palma Rifle Competition
The Palma discipline is a prone Iron Sight competition that originated in 1876, making it the second oldest continuing rifle match in the world. Except for a hiatus in the late 1900s, there is a nearly 150-year history of Palma matches. The Palma Course of Fire includes stages at 800, 900, and 1000 yards. At each yard-line you get two (2) sighting shots followed by 15 shots for record, for a grand total of 51 shots.
Under U.S.A. Palma rules the gun must be a rifle with metallic sights chambered for .308 Win (7.62×51) or .223 Rem (5.56×45). Most of the rifles featured in these videos are chambered for .308 Winchester, but we do have a video of John Whidden shooting his .223 Rem Palma gun — you’ll notice the significantly reduced recoil. CLICK HERE for more information on Palma Rules.
Here is Bryan Litz, creator of Applied Ballistics software, with his .308 win Palma rig.
Components of Modern Palma Rifle and Palma Competition Basics
We definitely recommend you watch this video. Hosted by SSG Robert Germanelo of the U.S. Marine Corps Shooting Team, this video explains the basic rules of Palma competition and covers the key features of a modern, tubegun-style Palma rifle. The featured rifle has a Eliseo Competition Machine stock, Krieger 30″ 1:13″-twist barrel, Defiance Machine single-shot Rem 700-compatible action, Jewell trigger, Warner Tool Aperture Rear Sight, and Stallings Machine “Right Sight” in the front.
John Whidden Shoots His Modern .223 Rem Palma Rifle
With the latest bullets, long barrels, and strong Lapua brass, the .223 Rem CAN compete successfully in modern Palma competition. Here we feature a .223 Rem Palma rig belonging to 5-time NRA Long Range Champion John Whidden. Watch video at 00:25 and you’ll see the recoil of Whidden’s .223 Rem Palma rifle is significantly less than a .308 Win Palma rig. John joked: “With the .223 Rem there is just a pop and a wiggle after the shot.” CLICK HERE for full 1200-word report on this rifle with many more photos.
Modern .308 Win Palma Rifle with Custom Anschutz-style Stock
Here a Palma competitor showcases his modern .308 Win Palma rifle built with an custom-made, Anschutz 1913 model-style stock with the main frame crafted by the host’s father. This rig has a 30″ barrel chambered for 155gr bullets. The video explains how the components were chosen, why the barrel is so long, and how the stock adjusts in numerous ways to fit the shooter’s particular prone style. Below is a diagram of the sight picture. This is covered at 1:56 in the video.
Palma Rifles Shooting 1000 Yards at Bisley in the UK
This UK-produced video features Palma matches at the Stickledown Range at Bisley. This video showcases the Inter-Counties match, where competitors use iron-sighted Palma rifles on targets at 1000 yards. This video provides a good introduction to the Palma discipline as practiced in Great Britain.
Canadian Palma Fun — Nova Scotia Shooters at 900 Yards
In this video, filmed at a beautiful range in Nova Scotia, two Canadian shooters compete at 900 yards with their iron sighted .308 Win Palma rifles. The video combines three different views into one frame, so you can simultaneously see downrange, see the shooters, and see the shot impact on the electronic target display. The shooters fired .308 Win cartridges loaded with Vihtavuori N140 powder and 155gr Sierra #2156 PALMA bullets.
Ballistics Guru Shoots Palma at 800 Yards
The talented Bryan Litz, head honcho of Applied Ballistics LLC, demonstrates his shooting skills in this video. Watch Byran complete the 800-yard phase of the Palma course shot at Camp Atterbury, Indiana in the summer of 2008.
Palma Chambering and Bullet Weight Limits
There is, understandably, quite a bit of confusion concerning caliber limitations for Palma rifles and Palma competition. Some folks say you can shoot a .308 Winchester (or 7.62×51) with a bullet weight up to 156 grains. Others say you can shoot a .308 Win (or 7.62×51) with any bullet weight. Still others opine that you can shoot EITHER a .223 Rem (5.56×45) or a .308 Win (or 7.62 NATO).
So who is right? Well, all these viewpoints are correct in part. That’s because different rules apply in different venues. In most, but not all United States Palma competitions, you can shoot either a .223 Rem or .308 Win with no restriction on bullet weights. But in some U.S. Matches, most notably the Spirit of America, certain prizes are limited to .308s with 156gr max bullet weights OR .223s with 81gr max bullet weights. What’s the bottom line? In most USA Palma competitions you can shoot either a .308 or a .223 with no limit on bullet weight. In International Palma competitions you can shoot either a .308 or a .223 but the max bullet weight is limited.
Many of our readers have never had a chance to shoot much past 600 yards. How far away does a 1000-yard+ target really seem to the naked eye? Well this short video answers that question. Gorilla Ammo, the video’s producers, used a camera-carrying aerial drone to fly downrange from the firing line all the way out to 1122 yards (and back again). Watch the drone footage at 0:00-0:07 and especially 0:48-1:03. The “bird’s-eye view” really gives you a sense of the distance. The “fly-back” at 0:48-1:03 time-mark is what makes this video worth watching.
The video features prone shooting at steel targets placed at 750 and 1122 yards. We do apologize for the lame, “oh so serious” voice-over which attempts to make this rather ordinary range session seem like some kind of life-changing experience. (Frankly, you may just want to turn the sound off — it’s that annoying.) It’s really not that big a deal to hit steel at 750 yards with a quality AR-15, chambered in .223 Rem, shooting Sierra 77 grain MatchKings.
Hitting Steel at 1122 Yards with 2540 FPS Ammo Can Be Challenging
The 1122-yard hits are a bit more impressive. Gorilla Ammo lists a relatively sedate 2540 fps Muzzle Velocity for its .223 Rem 77gr SMK ammunition. According to JBM Ballistics, at 1125 yards, that 2540 fps load has 68.3 MOA of drop from a 100-yard zero (firing at sea level and 80° F ambient). Moreover the bullet goes trans-sonic around 750 yards (losing stability) and is traveling just 933 fps at impact. And the wind’s the killer — at 1125 yards, with this bullet/load, a mere 2 mph, full-value wind change can move the Point of Impact over three feet!
Howa Model 1500 Mini Action rifles are popular with hunters and varminters. These rifles have smooth actions, very good 2-stage triggers, are lighter than most rifles, and are very affordable. And now Mini Action rifles are offered in the modern 22 ARC cartridge. Developed for the AR-15 and small actions, the 22 ARC is efficient and allows use of high-BC bullets in a very compact action. We think the 22 ARC is a great choice for a field-carried varmint rifle.
The Howa Mini Action series has been offered with a half-dozen chambering options and now the 22 ARC is available — a very good option for varmint shooting and small game. Hornady claims the 22 ARC outperforms all .22-caliber cartridges in its class. In the Mini Action, the 22 ARC rivals 22-250 performance, has dual-purpose match and varmint applications and is designed to take advantage of today’s long ogive, high-BC bullets with a variety of ammo offerings available from Hornady. Along with the 22 ARC, HOWA Mini Action rifles are offered in .223 Rem, 7.62×39, 6.5 Grendel, 6mm ARC, 350 Legend, 300 Blackout.
Howa 22 ARC Mini Action Features and Options:
Barrel Options: 22″ Steel, 20″ Light Varmint Steel, or 20″ Carbon Fiber Barrel (all 1:7″ twist). Threaded barrels are suppressor-ready.
Receiver (Action): Compact machined receiver with forged one-piece bolt and tool-less firing pin removal
Stock Options: Synthetic OD, Black & Yote dip, Walnut, Carbon Fiber, or APC Chassis
Trigger: Excellent two-stage trigger with 3-position safety
Magazine: Standard 5-round detachable magazine
HOWA Mini Action bolt is 09″ shorter than a short action, and 1.4″ shorter than a long action.
About the 22 ARC Cartridge
The 22 ARC (Advanced Rifle Cartridge) is a compact cartridge that fits into an AR-15 but is equally at home in a bolt action. The modern catridge shape is efficient and allows longer bullets to be fitted. The case capacity and sized offers performance, that rivals the 22-250. This makes the 22 ARC a good choice for varminters who want something with more punch than a .223 Remington case.
Hornady states: “The 22 ARC was engineered to use modern, high-BC bullets. Designing the cartridge and chamber in unison provides consistent accuracy, great velocity spreads and an outstanding shooting experience. This cartridge is the result of careful and meticulous design, following the same proven methodology as the highly acclaimed 6mm ARC.”
The 22 ARC is tailored to fit the AR-15 platform with a maximum overall length of 2.260″. In both ARs and bolt guns such as the Howa Mini, the cartridge should feed and function very well.
For many years, the U.S. Army Marksmanship Unit (USAMU) regularly published reloading “how-to” articles on the USAMU Facebook page. In this article, the USAMU’s reloading gurus address a question frequently asked by prospective handloaders: “Should I buy a single-stage press, or a progressive?” The USAMU says the best answer is Solomon-esque in both its wisdom and simplicity: “Get BOTH!” However, there is definitely more to the issue, as the USAMU explains below.
Progressive Press Safety Considerations
by USAMU Staff
Many are the beginning handloaders who have asked a friend about their “setting up” a progressive press for them. The idea is that the newbie could then just feed in components and crank out buckets of practice ammo without needing to really learn much about handloading. Tempting though this might be, that’s simply not how it works. Such an approach might be ok if there were never a malfunction with either press or operator, but that’s unrealistic. Our hypothetical newbie would then lack the knowledge to problem-solve most situations.
Worse yet, several different handloading operations would be occurring at different stations on the progressive press at the same time. It takes an experienced operator to keep track of, and truly understand the significance of, all those potential mini-problems. Loading without this experience is a recipe for potential disaster – such as a double powder charge (especially with pistol cartridges) dropped while the loader was attending to some other function, etc. Progressives are an animal unto themselves, and while they offer many benefits, they do take some getting used to – even by experienced handloaders!
ILLUSTRATIVE HORROR STORY
Here, enter a 40-year veteran handloader who decided to jump onto the progressive bandwagon late in his career, having used only single-stage presses all his life. A High Master NRA High Power Rifle competitor, he had no background in competitive pistol shooting, where historically most progressive presses are found.
Experienced Action Pistol shooters have typically encountered multiple episodes in which shooters “skipped” a powder charge for some reason, leading to a squib round and a bullet possibly lodged in the bore. Thus, at matches, it’s reflexive for them to yell “STOP!” in unison if they see a shooter get a “click” vs. a “bang”, and rack the slide to keep firing. This writer has personally seen several pistols saved in just such scenarios over the years.
Click No Bang — What NOT to Do
Our High Master set up a popular progressive press and began turning out .223 Rem 100-yard practice ammo with abandon. He was using a moly-coated 52gr match bullet and an economical, fast-burning surplus powder that gave great accuracy. Once on the range, he began practicing strings of rapid-fire. All was well, until he heard “Click!” rather than “Boom”.
Lacking the above experience or onlookers to halt him, he reflexively operated the charging handle on his expensive, custom NM AR15 Service Rifle, and the next trigger squeeze reportedly registered on seismographs over at least a three-state radius. He sat, uninjured but bewildered, until the hail of expensive bits and pieces quit raining down around him.
When the smoke cleared, he immediately cursed the horrid, evil, demonically-possessed progressive press for this, his first-ever reloading mishap. His $1400 NM upper was ruined, but thankfully, his $800 pre-ban lower… and he had escaped injury.
This tale is told not to discourage the use of progressive presses, but to emphasize the need to EASILY and IMMEDIATELY KNOW what is happening with the press at each station, every time the handle is cranked. Not to do so is, as they say, “bad ju-ju.”
It illustrates why we at the USAMU Handloading Shop agree in recommending that new handloaders should begin with a single-stage press. Once one thoroughly learns the steps in each phase of handloading by repeated experience, then one will be qualified to move on to a progressive press.
The single-stage press will REMAIN virtually indispensable for one’s entire handloading career, even after having purchased a progressive press (or two). There are endless small projects that are best handled on a single-stage press, and a poll of USAMU’s Handloading staff reveals that not one would willingly be without his single-stage press, despite owning at least one progressive.
In years past, the U.S. Army Marksmanship Unit published weekly reloading “how-to” article on the USAMU Facebook page. Here is a very informative USAMU article the subject of case lubrication. Tasked with producing thousands of rounds of ammo for team members, the USAMU’s reloading staff has developed very efficient procedures for lubricating large quantities of cases. This article reveals the USAMU’s clever “big-batch” lube methods. For other helpful hand-loading tips, visit the USAMU Facebook page on upcoming Wednesdays.
Rapid, High-Volume Case Lubrication
Today’s topic covers methods for quickly applying spray lube to cartridge cases prior to sizing. A typical order for this shop may be 25,000 rounds, so [speeding up] the lubrication process can be a real time-saver. While your ammunition lots probably aren’t this large, the efficient methods discussed here may help save a considerable amount of time over your handloading career. Our case lubrication rates range from 1500-1600 cases per hour, to 2400-2500 cases per hour, depending on caliber.
This shop uses virgin brass, whereas most home handloaders use fired brass, which necessitates some small changes at times. These will be discussed as they arise. Begin with fired brass that has been tumbled clean.
Ensure as much tumbling media as possible is removed from the brass, as when it gets into a size die, it can dent cases significantly. This is a good time to round out dents in the case mouths using a tapered tool to prevent damage from the decapping stem.
First, dump the clean cases into a large box or reloading bin. Shake the bin back and forth so that many cases are oriented with the mouths up. Next, pick up as many cases as is convenient with the mouths “up”, from natural clusters of correctly-oriented cases. With 7.62mm-size cases, this is usually 3-4, and with 5.56mm cases, this can be up to 8-10. Place the cases into the rack slots, mouth-up. Doing this in groups rather than singly saves considerable time. Once these clusters have been depleted, it will be time to re-shake the bin to orient more cases “up.”.
This photo shows a case lubrication rack made by a USAMU staffer.
Naturally, adjust the spacing to best fit the calibers you reload. We have found this size … convenient for handling through the various phases of case lubrication/transfer to progressive case feeders for processing. Note that the 1/2-inch angle does not cover much of the critical case area at the base, just forward of the extractor groove, where most re-sizing force will be exerted. As the USAMU uses virgin brass, less lubrication is required for our brass than would be needed for Full Length (FL) sizing of previously-fired brass.
NOTE: The amount applied using our rack is easily enough for our purpose. If using fired brass, be sure to adequately lube this base area to avoid having cases stick in the full-length sizing die.
Using a spray lube, coat the cases adequately, but not excessively, from all sides. Be sure to get some lube into the case mouths/necks, in order to reduce expander ball drag and case stretching/headspace changes. The spray lube this shop uses does not harm primers or powder, and does not require tumbling to remove after lubing.*
Take a close look at the photo above. The USAMU shop uses a common kitchen turntable, which allows the rack to be rotated easily. We place this in a custom-made box which prevents over-spray on to floors and walls.
Angled Box Method for Smaller Cases to be Neck-Sized
A refinement of the above method which especially speeds processing of 5.56x45mm cases is as follows. A small cardboard box which holds about 100 cases is fitted with an angled “floor” secured by tape. With the smaller 5.56mm cases, usually about 8-10 cases per handful can be picked up, already correctly-oriented, and placed into the box together. This prevents having to place them into the rack slots, saving time.
HOWEVER, note that this does not allow nearly as much lube access to the case bodies as does the rack. For our purposes — neck-sizing and setting neck tension on new brass, this works well. If using this procedure with fired brass, take steps to ensure adequate lube to prevent stuck cases.
As always, we hope this will help our fellow handloaders. Good luck, and good shooting!
*A two-part test performed here involved spraying primed cases heavily, while getting more lube into the case mouth/body than even a careless handloader would likely apply. The second part of the test involved literally spraying considerable quantities of the lube directly into the cases, drenching the primers. After a several-day wait to allow the lube to penetrate the primers, they were then fired in a test barrel. All fired normally; no unusual reports were noted. This bolstered confidence that normal amounts of the lube would not adversely affect our ammunition, and we have been pleased with the results over several years.
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
AR-15 Cartridge line-up image from 80% Arms, used with permission. This selection omits our favorite alternative — the 20 Practical (.223 Rem necked down to .204 Caliber).
Instead of using the standard .223 Remington or 5.56x45mm NATO round, you have many options for an AR-15, as shown above. This photo is from Complete Guide to Alternative AR-15 Rounds in the 80% Arms Blog. Some of the most notable alternative chamberings for AR-15s are:
20 Practical — Simply the .223 Rem necked down to .204 caliber. Requires new barrel. Same bolt, same magazines. Best Bang for the Buck. 6mm ARC — The 6mm ARC (from Hornady), is a SAAMI cartridge optimized for AR-platform rifles. The 6mm ARC is basically a 6.5 Grendel necked down to 6mm, with the shoulder moved back around .030″. 6.5 Grendel — Moderately expensive, 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. .50 Beowulf — The most expensive alternative AR-15 cartridge, this requires new barrel and bolt. The .50 Beowulf was created for game hunting, but most hunters use something more practical.
Of these five options, our top choice is the 20 Practical, followed by the 6.5 Grendel. 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
Many years back, 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. 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.
20 Practical in AR15 Demonstration Video
6mm ARC — Popular New SAAMI Cartridge Promoted by Hornady
The 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 magazines designed for 6.5 Grendel.
While 6-6.5 Grendel shooters are known to run stout pressures, the 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 is becoming a popular chambering in lightweight hunting rifles, such as the Howa 1500 Youth Model.
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.
Many visitors to the site ask us, “I’ve got a .223 and .308. What will a 6mmBR Norma (6BR) give me that I’m not getting already?” Well first you will probably average consistently smaller groups than your current .223 or .308 rifle (assuming the 6BR has a quality barrel and trigger). A good .308 Winchester can be superbly accurate, no question about that, but the lesser recoil of the 6BR works in the shooter’s favor over a long string of fire. Even with a Rem 700 or Savage action factory action, a 6BR with a benchrest stock, premium barrel, and a high-quality chambering job should deliver 5-shot groups in the high twos to mid-threes, provided you do your job. We have one 6BR rifle that shoots Lapua factory-loaded 6BR ammunition in the low twos and high ones. That’s exceptional, we admit, but it still shows how the 6BR is an inherently accurate cartridge, even with factory loads.
Compared to a .223, the 6BR offers a much better selection of high-BC projectiles, and will deliver considerably more power on the target. So it’s a better choice for hunters and 600-yard benchrest shooters. Compared to the .308 Win shooting 168gr MatchKings, a 6BR shooting 105-107gr bullets offers better ballistics all the way out to 1000 yards. Plus, for most people, the 6BR is just easier to shoot than a .308 Win. Recoil is less than half of the .308 Win cartridge. Both the .308 and 6BR chamberings offer good barrel life, but the 6BR uses 15-18 grains less powder, saving you money. On the other hand the .308 Win is the designated cartridge for F-TR and Palma shooting, so it may be a more versatile chambering for Long-Range competition. So which would we choose between the 6BR and the .308? Actually we think you should have both. The 6BR is a favorite cartridge out to 500 yards, and we like the .308 Win for F-TR. The .308 Win has shown outstanding accuracy, as displayed last week at the NRA F-class Nationals in Arizona.
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.
With good factory rifle ammo costing $1.30 per round or more — a Laser BoreSighter could pay for itself in just a couple range sessions.
Laser BoreSighters — fitted to your chamber — help you get on target more quickly, particularly with factory firearms. Just activate the unit, slip it into the chamber and look for the red dot on the target. The laser dot is about 2″ in diameter at 100 yards, and is visible even in full sunlight. Right now you can get HQ Issue Sight-Rite BoreSighters starting at $19.99 at Sportsman’s Guide (member price is $17.99). These units have a durable brass metal body and the battery will run an hour.
Rifle and Shotgun Cartridge Types:
Sight-Rite Boresighters are offered for popular rifle and shotgun cartridge types including: .17 HMR, .22 LR, .223 Rem, .204 Ruger, .22-250, 6.5 Creedmoor, 7mm WSM, .30-30, 20 Gauge shotshell, 12 Gauge Shotshell. Sportsman’s Guide also offers Sightmark Pistol Laser BoreSighters for $26.99: .38 SPL/.357 Mag, 9mm, .40 SW, .44 Magnum, .45 ACP.
Amazon offers MidTen Laser Boresighters complete with 6 batteries (two sets). This runs $17.99 for the .223 Rem cartridge while a larger boresighter for .25-06/.270 Win/.30-06 Boresighter is $19.89.
In-chamber BoreSighters are much safer than the kind that you insert in the end of the barrel (or attach to muzzle). If you forget your laser bore-sight placed in the end of the barrel, and then fire a round, you can blow up your barrel and/or suffer serious injury — it HAS happened.
This video shows how to use in-chamber Sightmark laser boresighters. The HQ Issue Sight-Rite XSI boresighters work the same way:
The 6mm ARC cartridge is a modern 
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Many visitors to the site ask us, “I’ve got a .223 and .308. What will a 6mmBR Norma (6BR) give me that I’m not getting already?” Well first you will probably average consistently smaller groups than your current .223 or .308 rifle (assuming the 6BR has a quality barrel and trigger). A good .308 Winchester can be superbly accurate, no question about that, but the lesser recoil of the 6BR works in the shooter’s favor over a long string of fire. Even with a Rem 700 or Savage action factory action, a 6BR with a benchrest stock, premium barrel, and a high-quality chambering job should deliver 5-shot groups in the high twos to mid-threes, provided you do your job. We have one 6BR rifle that shoots Lapua factory-loaded 6BR ammunition in the low twos and high ones. That’s exceptional, we admit, but it still shows how the 6BR is an inherently accurate cartridge, even with factory loads.
