The .224 Valkyrie is the most recent result of the continuing quest to wring more power and range from the AR-15 platform than provided by the original .223 Remington 5.56mm NATO chambering. While other attempts to improve AR-15 performance (some quite valid) have been met with yawns from much of the shooting public (and firearms manufacturers), the Valkyrie was enthusiastically embraced by serious riflemen and subsequently chambered in a wide variety of AR platforms and bolt rifles. Loaded Valkyrie cartridges easily meet, or come in under the 2.26-inch overall loaded length (OAL) threshold dictated by AR-15 detachable magazines, while also delivering more energy at much greater distances. Converting an existing .223 Remington 5.56mm AR-15 to .224 Valkyrie is no more difficult than pulling some pins, swapping uppers and adopting a 6.8 SPC magazine, which is exactly how the rifle used for this testing was created.

Federal brought us this cartridge, necking the 6.8 Remington SPC case to .224 caliber and sharpening shoulders to a seemingly-ideal 30-degree angle. And since Federal Premium has 6.8 SPC military contracts running into the millions of rounds with countries like Saudi Arabia and Jordan, parent cases are ultra-abundant, making the Valkyrie a more affordable shooting option than other souped-up AR rounds. A large portion of the Valkyrie’s mass appeal is in fast rifling twist rates in the neighborhood of 1:7, allowing the use of heavy-for-caliber bullets, though standard 55-grain bullets are certainly compatible.

Improved performance looks like 75-grain bullets pushed to nearly 3,000 fps and 90-grain bullets delivered at nearly 2,500 fps, allowing projectiles with a ballistic coefficient (BC) greater than .450 to remain supersonic to ranges out to about 1,300 yards. It does this while maintaining a pleasant shooting demeanor. Note that a 1:6.5 rifling twist may be necessary to stabilize some longer 90-grain bullets, particularly at elevations closer to sea level. Loaded with 60 to 62-grain polymer-tipped or hollowpoint bullets, the Valkyrie offers a wonderful long-range/windy day varmint option, while heavier numbers make it ready for light big-game duties, including pronghorn, deer and especially wild hogs, or for banging steel way out there.

The rifle used for load testing is pretty typical in the AR era, a rifle my father built from an Anderson Manufacturing lower and replacement .224 Valkyrie upper. The 22-inch, stainless steel barrel includes a medium-contour, 1:7 twist, full-length flutes and is threaded to hold a muzzle brake or suppressor. A Luth-AR buttstock with adjustable LOP and comb height and 15-inch M-Lok forend were added. I set a Trijicon AccuPoint 2.5-12.5x 42mm scope in Precision Hardcore Gear Black Opps 30mm rings for testing.

New Starline brass and Federal Premium GM205MAR AR-Match Small Rifle primers were used throughout. These primer’s AR designation indicates a harder cup material to guard against slam fires while auto-cycling in AR platforms. Once-fired Starline brass held an average of 30.7 grains of water, filled to the rim and with a spent primer in place, compared to 31.7 and 31.1 grains average for once-fired Federal brass and nickel-plated cases resulting from once-fired factory ammunition. Ten new, unprimed Starline brass showed a weight deviation of just one grain. A Redding Premium FL Die Set was used to assemble rounds, the seating die including a micro-adjustable head that can be dialed to the nearest 1/1000 of an inch.

Due to the Valkyrie’s newer status, nearly all load data involves modern, temperature-insensitive propellants with cleaner burning properties and/or copper-erasing agents. All powders used were either ball-type or fine stick powders that meter consistency through progressive-press throwers, allowing smoother volume loading. Test bullets included one 62-grain varmint hollowpoint, the remainder chosen to take advantage of the Valkyrie’s long-range talents and weighing 75 to 90 grains with BCs ranging from .362 to .585.

Nosler’s 62-grain Varmegeddon is an explosive, flat-base varmint bullet with a .251 BC. This bullet didn’t produce the smallest groups in this test, but a handful of loads were certainly accurate enough to snipe varmints out to 300-350 yards (Federal factory loads with Nosler 60-grain Ballistic Tips produced tighter groups, a bullet with a higher BC). The best group with this bullet was created by 26 grains of Vihtavuori N-540, measuring .74-inch at 2,882 fps. A charge of 25.5 grains of Shooter’s World Match Rifle clustered .76-inch at 3,110 fps. Twenty-five grains of Alliant Power Pro Varmint and 26.5 grains of Accurate 2520 grouped less than an inch at velocities ranging from 2,756 to 2,904 fps, respectively. Of note, my initial assumption that seating bullets to fit the AR magazine with room to spare would also chamber in the Valkyrie proved wrong. The rounded ogive of this relatively short bullet required seating nearly .20-inch shorter than the maximum 2.26 inches, even an OAL only .095-inch longer than the adopted 2.065 inches failed to chamber fully and allow the rifle to fire. Extraction then became challenging.