Hornady's 22 ARC: The Best .22 Cartridge of the Decade?

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The clever ballistic wizards at Hornady developed the 6mm ARC in 2020 to fit the AR-15 platform (it also works well in bolt-action guns). The case design was developed to provide the highest velocities and best long-range performance that could be housed in the AR-15 platform. From that case, the .22 ARC was born, and its lineage goes back even farther than that.

The 7.62x39 was introduced in 1943 and was reformed into the .22 Russian (aka the 5.6x39 Vostok) in 1961. Benchresters Dr. Louis Palmisano and Ferris Pindell modified the .22 Russian into the .22 PPC and necked up that case to make the 6mm PPC in 1987. The 6mm PPC case was necked up to form the 6.5 Grendel in 2002. The 6.5 Grendel was necked down to form the 6mm ARC in 2020, and the 6mm ARC was subsequently necked down to .22 caliber to make the .22 ARC in 2024. Thus, the .22 ARC has a solid pedigree in pinpoint accuracy, excellent long-range ballistics and power, and commercial versatility.

Case Design

The .22 ARC case is reminiscent of its progenitors. Hornady points out that the long throat of the case design allows long-for-­caliber bullets to be seated out to the maximum length for an AR-15 magazine, i.e., 2.26 inches. This makes it suitable for bullet weights that were previously unheard of for a .22-caliber cartridge. Data are listed for 75-, 77-, 80-, 88-, and 90-grain bullets. (There is a limit to this fast-twist benefit, as I will discuss later.) Varmint hunters, fear not, as loads for 53-, 55-, and 62-grain bullets are provided, at velocities that approach .22-250 Remington speeds.In addition, with the proper bullets, the .22 ARC is entirely suitable for hunting medium-sized big game, such as deer, pronghorned antelope, javelinas, and feral hogs.

The .22 ARC’s maximum case length is 1.525 inches, and as one would expect, it has the same base diameter as the 6mm ARC (just 0.003 inch larger than the 6.5 Grendel). The .22 ARC has a neck length of 0.221 inch, which is very close to the ideal one-caliber neck length (0.224 inch) that is thought to enhance accuracy and provide a uniform bullet pull. The shoulder angle is the now-customary 30 degrees, typical of modern, high-­performance cartridges. Significantly, the case and chamber neck specifications mimic the close tolerances of the justly famous 6.5 Creedmoor, also a Hornady development. The .22 ARC’s case max OD is 0.253 inch, while that dimension in the chamber is 0.254 inch, so the bullet doesn’t have room to “wander around” looking for the rifling when it’s fired.

Pressure Data

The maximum average pressure (MAP) set by SAAMI for the .22 ARC is 52,000 psi. However, recognizing the dual applicability of the versatile .22 ARC to both ARs and bolt-action guns, Hornady developed two sets of pressure-tested load data, one for gas guns at the SAAMI MAP and another data set for bolt actions, at 62,000 psi. All these data are available free on the Hornady website.

Handloaders are cautioned not to confuse or mix up these two distinct and precise data sets. Maximum means maximum. At least five different factory loads for the .22 ARC are available from Hornady. To my knowledge, no other firm offers ammo as I write this.

Available Guns

It is common for new cartridges to be orphans for a while. By that I mean gun companies seem to wait to see if a cartridge is going to be popular before making guns chambered for it. So one might ask, “How can a cartridge become popular if there are few guns to shoot it?”

Thankfully, several companies now make guns for the .22 ARC. ARs are relatively available, at various price levels. I like ARs, but traditional bolt actions are more practical test beds for me. Thus, I ordered a new Ruger American Gen II in .22 ARC for this report. I have several other Ruger American Rifles, so I was confident that this new one would be a sound investment. I was right.

In addition to Ruger, Howa lists five different versions of its Mini Action bolt actions chambered for the .22 ARC. We have a Howa test rifle on order, and we’ll report on it in due time. All feature the standard 1:7-inch twist for the .22 ARC. Three versions that I’d classify as “hunting rifles” come with 20- or 22-inch threaded barrels. Three have synthetic stocks. The “Yote” model has a nice camo pattern, the Synthetic has a brown stock, and the Carbon Fiber has a leafy camo finish. Then there is the APC that is, well, an assemblage of parts. A chassis rifle? My pick of the litter would be the Walnut model with its (big surprise) walnut stock that looks like a traditional classic style. The Howa Mini rifles are also available in .223 Rem., 6mm ARC, 7.62x39, 6.5 Grendel, and .350 Legend.

My new American Gen II is the Predator version, so it has a 24-inch barrel with a 2-inch muzzle brake. The barrel is gracefully fluted and mikes 0.676 inch at the muzzle behind the muzzle brake. The twist rate is 1:7. The barrel and action have a Bronze Cerakote finish, and the stock sports Ruger’s Green Splatter pattern. They give the rifle quite an attractive appearance.

One magazine from Duramag is supplied. Not surprisingly, the magazine is marked “6.5 Grendel” on the side. The magazine’s capacity is 10 rounds, and if your fingers are tough enough, you can indeed stuff 10 rounds into it. I tried an E-Lander AR-15 magazine for the 6.5 Grendel (it holds 20 rounds), and loading this magazine is twice as much fun as loading the 10-rounder. Note that due to the design, you can’t close the bolt on either of these magazines when they are empty.

The trigger pull weight on my gun fresh out of the box was 3 pounds, 11 ounces and was perfectly serviceable as is. However, Ruger says that the American’s Marksman trigger is user adjustable from 3 to 5 pounds, so I removed the stock and adjusted the pull-weight screw out a bit, reducing the pull weight to 3 pounds, 3 ounces. It seemed noticeably lighter. This factory trigger gets a gold star from me, but confirmed do-it-yourselfers can get a drop-in replacement trigger from Timney that’s adjustable from 2 to 4 pounds.

The American Rifle as received weighed 6 pounds, 8 ounces. I installed a Trijicon Tenmile 3-18X 44mm scope in Leupold 30mm rings for testing, and that brought the weight up to 8 pounds, 12 ounces. (Confession: Once testing for this report is finished, I will replace that scope with a lighter weight one.) The receiver comes with a multi-slotted Picatinny rail, but it also is drilled and tapped for stronger 8-40 screws. Weaver No. 46 bases fit, both front and back, with the rail removed.

For my accuracy-testing sessions, I skipped loading magazines by installing one of my favorite add-ons for the short-action Ruger American called the Ruger One-Shot Sled (part no. PM858). Just remove the magazine well and replace it with the sled holder. The sled then snaps into place, and presto, you have a single-shot rifle. This takes about five minutes, if you don’t hurry, and in my opinion, the One-Shot Sled makes bench testing easier.

Range Results

I obtained Hornady’s five factory loads, and I also handloaded several combinations of suitable bullets and powders. I fired five-shot groups off of a Lead Sled DFT 2 from inside my shooting building. Bullet speeds were measured with an Oehler M35P Chronograph. The start screen was set at eight feet from the gun’s muzzle, and the screen spacing was four feet.

The bore was cleaned after every three groups, and I checked the bore occasionally during testing with my Hawkeye borescope. Thankfully, the American’s bore did not collect much jacket fouling, and it was very easy to clean. Some loads were tested in some rather gusty winds, but all holes in paper counted. Several “one-hole groups” were spoiled by an errant flyer–totally due to shooter error and not the rifle, scope, or ammo. The results of my shooting sessions are shown in the accompanying chart.

Varmint hunters have the 62-grain ELD-VT. A long-range load for larger varmints is the Black ammo loaded with the 75-grain V-Match bullet. The long-range match load shoots the 88-grain V-Match bullet. Hunting loads include the monolithic copper alloy (lead-free) 70-grain CX and the 80-grain ELD-X bullets. Overall average accuracy for all the factory loads was 0.61 inch. It’s getting harder and harder to beat factory loads with handloads these days!

But speaking of handloading, refilling fired .22 ARC cases is a snap. I used Hornady and RCBS dies, and both worked perfectly. Correct sizing was determined with Hornady’s Lock-N-Load Headspace Comparator because a modified case for the .22 ARC for this tool is already available from Hornady. Determining the cartridge overall length (COL) for individual bullets to touch the rifling was easily done with Hornady’s Bullet Comparator. These two tools are great time-savers.

The maximum COL for the round set by SAAMI is 2.26 inches, in deference to AR magazines. The Ruger/Duramag magazine has an internal length of 2.33 inches, so one can fudge a bit on COL with it. Not so with the E-Lander mag; stick with 2.26 inches, or less, for that. For COL, a good rule of thumb for seating depth is to start at 0.01 inch off the lands, which is what I used for all but two of my test loads. These bullets were seated to the base of the case neck. Bullet jumps are noted in the chart. Interestingly, the group sizes of the two loads with a bullet jump of 0.050 inch were just as good as most of the loads with a bullet jump of 0.01 inch.

All handloads used Hornady cases from fired factory ammo, and I used Federal 205 Small Rifle primers for all handloads. The ballistic uniformity, as expressed as the coefficient of variation (COV), averaged a delightful 0.69 percent for the 68- to 88-grain bullets and 0.63 percent for the factory loads. COV is the standard deviation expressed as a percentage of the average velocity. Anything around 1 to 2 percent is good, and less than 1 percent is really good.

There is a multitude of 0.224-inch bullets available, and most will work in the .22 ARC. From lightweight speedsters to the new long, skinny ones, there is a projectile for just about any shooting purpose. Standouts in my tests were the Hornady 68-grain BTHP, Sierra 69-grain MatchKing, Hornady 75-grain ELD Match, Berger 85.5-grain Long Range Target, and the Hornady 88-grain ELD Match. But there weren’t any “bad” ones. Overall, I was impressed with the uniform accuracy of the round in the American Rifle.

Lots of powders are suitable for loading the .22 ARC, but after much rangetime, I think one could concentrate on CFE-223, LEVERevolution, StaBALL 6.5, and StaBALL Match. That said, all is not wine and roses. Recall that the .22 ARC has a 1:7-inch twist, and as I noted earlier, there is a limit to its applicability. The Sierra 90-grain BTHP MatchKing has a note printed on its box that recommends a 1:6.5-inch twist. Okay, but I just had to try this sleek bullet anyway. The average group size for the four loads I tried was 1.36 inches. Next time, I’ll pay attention to any messages on bullet boxes. Interestingly, the Hornady 88-grain ELD Match bullet shot just fine in the 1:7-inch twist. The average group size for all 12 other handloads was 0.68 inch, and many were around 0.50 inch.

The velocities of my handloads were typically a bit slower that those listed in the 2025 edition of the Hodgdon Annual Manual and in Hornady’s online data, but my loads looked like a good working maxima in my rifle, and I can’t complain about the accuracy. My only nit to pick is with the American’s extractor. Early on, as the bolt was closed on a round, it was very hard to snap the extractor over the cartridge case’s rim. However, as testing progressed, it smoothed up quite a bit and presented no problems. For shooters looking for a versatile small-bore cartridge for a multitude of chores, the test data confirm that the new .22 ARC deserves a serious look. Great factory fodder is available, the round is a delight to handload, high-tech bullets are available, and the Ruger American’s accuracy is a known quantity.                             

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