Faxon Gunner 16" 1:8 338 ARC Barrel

The Faxon Gunner 16" .338 ARC barrel is the do-it-all length for Hornady's .338 ARC cartridge, a thick-jacketed .30+ caliber AR-15 round that runs on 6.5 Grendel Type 2 (.136) bolts and feeds from DuraMag 400 Legend magazines. At 16 inches it clears the federal rifle barrel-length minimum, so it builds into a standard rifle with no NFA paperwork. This is the length to pair with the supersonic 175gr BLACK load when you want full-power performance from a conventional carbine.

The 1:8 twist is Hornady's official .338 ARC rate, chosen to stabilize the entire factory load range. Hornady specifies 1:8 to fully stabilize the heavy 307gr Sub-X subsonic projectile as well as the 175gr BLACK supersonic, which makes this barrel the all-rounder of the lineup rather than a load-specific option. Faster barrel-maker twists like 1:5 exist, but they are a short-barrel subsonic terminal-performance choice, not Hornady's general-purpose spec.

Constructed from 416R stainless steel with a QPQ nitride finish and 5R rifling, the Gunner profile splits the difference between a pencil and a government contour to keep weight down without the harmonic instability of an ultra-thin barrel. The pistol-length gas system and 5/8x24 muzzle threads follow the conventional .338 ARC build recipe, so .338 ARC muzzle devices and a .338-rated (.36-bore) suppressor thread on directly. The bullet is .338 inches, larger than a .30-cal bore, so a .30-caliber can is not rated for it; pair a .338 Lapua-rated modular can like the SilencerCo Omega 36M.