Fouling Shots

I kind of backed into my most recent rifle acquisition when Hornady sent me a few complimentary boxes of 22 ARC ammunition upon the company’s announcement of the brand-new cartridge earlier in 2024. As a matter of good taste, I then felt it would behoove me to buy, borrow or build a rifle in 22 ARC to shoot the ammo for a product review. An AR-15 barrel seemed the way to go for several reasons: I could build an upper on a 22 ARC barrel for less than buying a complete upper, and because the AR-15 is the 22 ARC’s natural habitat, anyway. Besides, nobody yet had a 22 ARC rifle of any kind in production.

It appears Hornady’s new ammunition also caught barrel makers unprepared. Queries to barrel and rifle makers recommended by Hornady all garnered “not yet” responses. Two months and $600 later, an AR-15 barrel, BCG (bolt carrier group) and a magazine from Odin Works landed on my doorstep. With a dozen other projects and deadlines clamoring for my attention, by the time I got around to building the upper and taking it to the range with Hornady’s complimentary ammunition, other writers more excited about the 22 ARC utterly scooped me. Wolfe Publishing’s Editor Jeremiah Polacek pounced on the 22 ARC and, in Handloader No. 351 (August 2024), published his first of two reports on the cartridge, to include 37 handloads, most of which outperform Hornady’s excellent factory loads. I don’t think I can add any thunder to that.

The 22 ARC’s tagline and raison d’être is “near 22-250 performance from your AR-15,” which is an admirable pursuit and surely a very satisfying accomplishment for the engineers involved in making the cartridge work with the AR-15’s gas system. Therein, we have the two challenges surmounted by very niche cartridges intended for the AR-15: (1) Achieving bolt action rifle cartridge downrange performance and (2) the limiting factor of the rifle’s gas system and overall comparatively light construction.

Interestingly enough, a great many people think the AR-15 is a semiautomatic copy of the M-16 military rifle when the opposite is true – the Armalite Rifle (AR) actually came first. The US Army took notice of the AR and decided Mr. Stoner’s design would make a fine select-fire battle rifle. Despite tragic early battlefield failures in Vietnam related to the cartridge, the rifle and its 5.56 NATO cartridge improved, and given the millions of M-16s still on and entering active duty around the world, it does, indeed, make a fine battle rifle. Within its design parameters, it continues to evolve to fulfill mission-specific roles.

Without a doubt, the AR-15 is America’s rifle – its modularity making it probably the most adaptable and versatile rifle ever devised – and continues to drive its popularity among the citizenry. The only aftermarket part not yet seen on an AR-15 is a solar-powered espresso maker, and if someone eventually makes one attachable to an M-LOK or Picatinny rail, it will sell. Heck, I’d probably buy one. The rifle continues to host new cartridges intended specifically for it, the latest and greatest (at this moment, anyway) being the 22 ARC.

Niche cartridges for specific rifles are nothing new, and they typically start as wildcats. Two that come to mind are the 35 Whelen and the O’Neil 33-50 Magnum, aka 33 Caliber Mauser. The intent behind both is the same as the 22 ARC – to get more performance from specific rifles, in these cases, plentiful and cheap military surplus bolt actions. The 35 Whelen is a necked-up 30-06, intended to fit perfectly in military surplus Springfield rifles with nothing more than a barrel change (or reboring and rechambering). The O’Neil 33-50 Magnum did the same for military surplus Model 98 Mauser rifles and the 8x57 cartridge. No deer or elk would be able to tell the difference between the two. Still, the 35 Whelen eventually became a legitimized factory cartridge, while you’ve likely never heard of the O’Neil 33-50 Magnum.

The 22 ARC case is not new. Expressed biblically, the 7.62x39mm Soviet case begat the 6.5 Grendel, begat the 6mm ARC, begat the 22 ARC. We might also toss in a begotten cousin, the 224 Grendel; and an uncle, the 22 PPC; as they, too, utilize the Soviet case. Among these, I see absent from SAAMI standards the 224 Grendel, leaving it in the same “un-legitimized” wildcat realm as the O’Neil 33-50 Magnum, and perhaps to suffer the same fate of a future ignominious question, “The 224 what?”

When I first started competing in High Power with the M-14 rifle, everybody knew the M-16 “mouse gun” could never shoot competitively at 600 yards. It turns out everybody was wrong because it was the 5.56 NATO cartridge with its 55- or 62-grain bullet that couldn’t compete at that distance. Once competitors went to heavier 69-grain bullets and faster twists, match-tuned M-16s eventually edged out the M-14. At serious High Power matches today, it’s all M-16/AR-15 for the Service Rifle category; M-14s are nonexistent, and civilian clone M1A rifles are as common as furry frogs, though throwback rifles do appear at informal club and CMP matches.

High Power winners today are shooting .223-inch bullets weighing 75 and 77 grains and more. Twist rates have increased from the M-16’s original 1:14 to accommodate the heavier bullets and are now twice that, with some twists at 1:6.5 for high ballistic coefficient (BC) bullets of 80.5 and even 90 grains. Hornady loads some 22 ARC with 62-grain bullets, but its real design purpose is to launch heavy .223-inch bullets weighing 75 to 90 grains. I note Hornady 75- and 88-grain loads are the ones that bear the word “Match” on the box.

Hornady’s new 22 ARC is the culmination of decades of work by numberless individuals seeking ever-longer range precision from the .223-inch bullet in the AR-15. Yet, there’s more. SAAMI maximum average pressure for the 22 ARC is 52,000 psi in deference to the AR-15’s gas recoil system and light construction. Hornady load data specifically for bolt action rifles raises the bar to 62,000 psi, adding legs and speed to the 22 ARC not wise to pursue in the AR-15, such as sending an 80-grain bullet in excess of 3,000 fps.

Has Hornady’s 22 ARC achieved the upper limit of the long-range .223-bulleted cartridge in the AR-15? Having learned a lesson from disdaining the “mouse gun” for competition, I’ll refrain from making a prediction here.