Fn15 16 Carbine Upper (hf Barrel)

The FN15 16 Carbine Upper is a complete 5.56x45mm upper receiver assembly built to drop onto any mil-spec AR-15 lower. It targets shooters who want a factory-finished FN AR upper without sourcing and assembling parts piecemeal. FN America builds this unit on the same manufacturing line that produces military M4 and M16 components, so the bolt and carrier group carry the same testing pedigree found on issued rifles. With a 16-inch barrel and a free-floated handguard, it slots into duty, defensive, and range builds where reliability under sustained fire matters more than weight savings.

The barrel is FN America's signature cold hammer-forged, chrome-lined profile cut from proprietary steel, with a 1:7 right-hand twist that stabilizes everything from 55-grain to heavier 77-grain match loads. Operation is direct impingement on a mid-length gas system paired with an H buffer, a combination that softens the recoil impulse and slows bolt unlocking compared to carbine-length gas. The barrel sits fully free-floated inside a Hodge Defense-designed wedge-lock handguard, secured by a proprietary barrel nut with anti-rotation hardware. That handguard gives continuous 12 o'clock rail space and multiple M-LOK slots for lights, lasers, and grips. The complete assembly weighs 4.35 lbs and ships with an ambidextrous charging handle and an M16-style bolt carrier group. Pair it with a quality buffer and spring from our rifle parts selection.

This upper suits a patrol carbine, a home-defense AR, or a 3-gun build where a free-float forend and mid-length gas help with follow-up shots. Because it arrives complete, the only work left is mating it to a finished lower and adding optics and a muzzle device. Sort your sighting setup from our optics options, then round out the build with cleaning gear and lubricants from our cleaning supplies. If you need fasteners or small components, our AR-15 barrel hardware covers the details that keep a build running.