6mm ARC (AR Loads) (Handloader Issue #331)

6mm ARC (AR Loads) (Handloader Issue #331)

The 6mm ARC (Advanced Rifle Cartridge), tailored for the AR-15 platform, was the focus of an extensive feature in Handloader Issue #331 (April 2021), where its performance in semi-automatic rifles was explored in depth. As Hornady’s modern solution for a flatter-shooting, low-recoil cartridge in a compact platform, the ARC’s performance in AR-style rifles continues to generate interest from reloaders and competitive shooters alike. The article highlights several powder and bullet combinations that maximize the round’s efficiency and accuracy from 16- to 20-inch barrels.

The data emphasizes the cartridge’s compatibility with 6mm projectiles in the 90- to 108-grain range, especially Berger and Hornady match bullets, noting optimal results with powders like CFE 223, Varget, and H-4895. Load development was done with AR-15s equipped with Grendel-type bolts and proper magazines, keeping within SAAMI pressure limits while achieving excellent ballistic consistency and sub-MOA accuracy in some platforms. Barrel twist rates of 1:7 or 1:8 were recommended to fully stabilize the longer high-BC bullets.

The report also noted that while the 6mm ARC’s case capacity limits velocity compared to full-size bolt-action cartridges, its efficiency and low recoil make it ideal for rapid follow-up shots and extended range engagement — particularly valuable in the gas-operated AR system. Several factory loads were evaluated alongside handloads, with handloads typically showing superior group sizes when matched to specific barrel lengths and chamber throats.

Overall, the piece in Handloader #331 supports the 6mm ARC’s growing popularity as a versatile performer in both gas guns and bolt rifles. For AR reloaders, the cartridge offers a rare balance of reach, precision, and shootability, with ample data now available to fine-tune it for various mission profiles — from competition and varmint hunting to mid-range tactical use.