The made-from-scratch 6.8 Remington SPC case provided the basis for the relatively new 224 Valkyrie, brought to us by Federal Cartridge. It was introduced in 2018, to much fanfare and initially chambered in MSR/AR-15 rifles. Like many AR-15 inspired cartridges, the Valkyrie was developed to place energy on target beyond 223 Remington 5.56x 45mm NATO capabilities. To do this, Federal introduced heavy-for-caliber bullets up to 90 grains, while Savage (at the time under the Vista Outdoor umbrella, which also houses Federal) provided the 1:7 rifling twist needed to stabilize long-for-caliber projectiles. The result was a cartridge that remained supersonic to 1,300 yards while firing high-ballistic coefficient (BC) 90-grain bullets sent from 18-inch barrels.

My initial interest in the Valkyrie stemmed from the ability to send high-BC bullets downrange at decent velocities to minimize bullet drop and wind drift while shooting long-range varmints such as high plains prairie dogs. My first extensive testing involved an Italian-made Franchi Momentum Elite Varmint with a 24-inch, 1:7-twist barrel, which assembled a good number of impressive groups, but proved finicky overall. I had also worked up loads for an early AR-15 with worthwhile results – though again, the round seemed particularly finicky.

More recently, I became interested in the 224 Valkyrie as a wild hog round, sparked by frequent trips to Texas to help friends cull the invasive species while shooting thermal-equipped AR rifles. Typical AR-15 rifles include barrels as short as 16 to 18 inches, which result in velocities slower than my observations with the bolt rifle. The round generally gains 25 to 30 feet per second (fps) per inch of barrel added. To split the difference between appealing turn-bolt velocity and the convenience of quick AR follow-up while addressing large sounders of hogs, I equipped the test rifle with a fluted 22-inch stainless steel barrel with 1:7 twist. To its ½x28 muzzle threads, I added a Bowden Tactical AR-chitect Linear Compensator that does an admirable job of directing muzzle blast/report away from the shooter and allows hunting without hearing protection. Adding a full-on suppressor made this AR a mite long for private land truck work, so the compensator proved a great compromise.

This parts build rifle was based on a DPMS Panther Arms lower and unmarked flat-top upper I had picked up cheaply. I added a Velocity MPC Trigger with forward-positioned trigger shoe to better accommodate my large mitts and provide a crisp 3½-pound pull. The pistol grip was a tan ERGO, the buttstock was a tan FAB Defense RAPS with adjustable comb and length of pull set to fit my lanky frame. A Steiner 3-15x 50mm T5Xi scope was mounted in a 34mm Nightforce Ultralight Uni-Mount and bolted to the integral Picatinny rail. The Uni-Mount allows easy removal/return without losing zero when swapping between the optic and thermal units used during nighttime Texas operations.

Federal Premium offers Barnes 78-grain TSX and Fusion 90-grain loads for big-game duties. Here, I wished to discover handloads suited specifically to wild boars, which would also make them appropriate for big game from delicate pronghorn to beefier mule deer and Midwest whitetails. I also strived to introduce as many modern, temperature-stable/clean-burning (including decoppering formulas) powders as possible. Powders were chosen largely on the promise of top velocity/maximum energy delivery important to clean kills on 100- to 300-pound game.

Federal brass collected from once-fired factory loads was used for all loads. These cases hold small rifle primers, Federal Ammunition No. 205 Small Rifle primers chosen for this round of testing. The Federal cases held about 29.5 grains of water when filled to the brim and with spent primer in place, while once-fired Starline brass on hand held about a grain more.

My primary objective – wild hogs weighing up to 300 pounds – guided bullet choice, including a mix of bonded-lead core, monolithic copper and cup-and-core designs promising a large percentage of retained weight after passing through animals or encountering bone. These included Swift Bullets’ 62-grain Scirocco II, Quality Cartridge’s 68-grain Game-StopR, Speer’s 75-grain Gold Dot, Rocky Mountain Reloading’s (RMR) 75-grain 3 Gun Hunter (3GH) and Federal’s 90-grain Fusion. The bullets’ overall lengths are mentioned below in direct relation to the limited dimensions of the 6.8 SPC magazines used in compatible AR-15 rifles.

This Valkyrie rifle, again, proved frustratingly finicky, with any group coming in at 1.50 inches or less deemed acceptable for my goals.

Swift’s long-for-weight (.96 inch) 62-grain Scirocco II included a thick, tapered copper jacket chemically fused to a lead core to ensure high-weight retention and deep-driving penetration. A boat-tail/poly-tip profile created a streamlined .307 G1 BC, the black tip initiating expansion to create a mushroom approximately double its starting diameter. Swift recommends a 1:8 twist for this bullet. Serving as fuel were Hodgdon LEVERevolution, Alliant Powder Pro Varmint, and Hodgdon Varget – all promising top velocities. The overall group average with this bullet was 1.42 inches. Power Pro Varmint gave the worst showing, its best group was 1.23 inches at 2,857 fps with 24.5 grains of powder, the maximum load of 25.5 grains printing into 1.57 inches at 3,029 fps. Varget did better, its best group 1.01 inches at 2,999 fps. LEVERevolution produced the best group of the test, 27.5 grains pushing the Swift to 3,188 fps and grouping into .40 inch, making that load an easy choice with this bullet.