Accuracy-wise, the CMMG consistently shot sub-1″ groups at 100 yds. for the first three shots, but if I fired quickly, it would begin stringing the fourth and fifth shots vertically so that five-shot groups stretched to 1.6″. If I let the barrel cool several minutes between rounds, my five-shot groups shrunk back down to 1.2″. Keep in mind, however, that this cartridge is so new that I only had two loads—the only two available at the time—to test. I’d sure like to see how the ARC performs in a benchrest-style, micro-length bolt gun as well. With 5 lbs. of recoil from a 12-lb., 1,000-yd. rifle, that’d sure be fun.
Even after installing an AB Suppressor on the Resolute, I experienced no jams, misfeeds or failures to fire in more than 400 rounds, proving the round and the CMMG’s bolt and chamber specs are sound, as well as the Resolute’s overall reliability. Ultimately, I added Dueck offset ghost-ring sights, an Armageddon sling and a Magpul bipod to the carbine, and, as such, it’s just about the ultimate, lightweight, do-all-rifle and chambering for me. With a swap to a red-dot sight, I can’t think of a finer home-defense carbine, either.
But do I think the 6mm ARC is the end-all cartridge? No, because I love to see any and all small arms innovation, and I’m sure something great will follow. Would I buy it if I already had a Grendel? Maybe, maybe not, depending on if it becomes popular enough that ammunition and a healthy selection of loads can be readily found. At the time of this writing, the following manufacturers are supporting 6 mm ARC: Adams Arms, APF Armory, Barrett, Brownells, Christensen, CMC Triggers, CMMG, GAP, Geissele, Howa, Lantac, Mile High Shooting Accessories, Mossberg, NEMO, Noveske, Odin Works, Proof Research, Radical Firearms, Ruger, SanTan Tactical, Seekins Precision, Uintah Precision and Wilson Combat. I do, however, think it’s the best all-around cartridge for the AR to date; better than the .223 Rem., 6.5 mm Grendel, 6.8 SPC and .300 Blackout, and evidently Hornady and I aren’t the only ones who think so.
In June, the U.S. Department of Defense adopted the 6mm ARC cartridge. No one knows how it will be received by hunters and shooters in the months and years to come, but I do know that the hogs, coyotes and steel targets around my place are in a heap of trouble.