An FN button-rifled AR-15 barrel in 5.56mm, 10.5 inches, with an M16 profile and carbine-length gas system. FN manufactures barrels for the US military M16 and M4 programs, which means the company's civilian barrel offerings come out of a facility that has to hold military specification day in and day out.

A 10.5-inch barrel is the classic short-barreled rifle and pistol length, giving up velocity in exchange for a genuinely compact package, and the carbine gas system is properly matched to that length. Building a 10.5-inch rifle requires an SBR registration or a pistol configuration; confirm your build plan complies with federal and state law.

In stock and ready to ship straight to your door from Dawson Defense, an Arizona-owned licensed dealer.