White Label Armory 13.7" 5.56 Government Mid-length Barrel

White Label Armory's 13.7" barrel is a mid-length barrel that keeps a carbine short when paired with a pinned and welded device. It is chambered in 5.56 NATO with a 1:7 right-hand twist, turned from 4150 CMV steel to a Government profile, and black nitrided. The mid-length gas system runs through a .750" gas block journal with a .074" port, the barrel extension has M4 feed ramps, and the muzzle carries 1/2x28 threads and an 11-degree target crown. WLA lists it at 24.5 oz bare.

Pair it with a mid-length gas tube and a gas block sized to the barrel's journal. The 1:7 twist stabilizes the full common range of 5.56 bullet weights, and the 1/2x28 threads take standard 5.56 flash hiders, brakes, and suppressor mounts. At 13.7" the barrel needs a muzzle device pinned and welded to reach the 16" federal rifle minimum, which takes a device extending at least 2.3" past the muzzle; otherwise it builds a short-barreled rifle or a pistol. Check your state's law before building it short.