SKU: 80001442
UPC: 050806500747
MPN: BN-BRN4556-14.5
The Brownells BRN-4 14.5" medium profile barrel is a 5.56 NATO chambered barrel built for shooters assembling an HK416-pattern rifle. Manufactured by Faxon for Brownells, it mirrors the dimensions of the original 416 barrel while running a slimmer medium contour to shed weight and keep the build balanced. At 14.5 inches it sits in the carbine-to-mid range that suits both range work and duty-style use, and it accepts standard muzzle devices through its 1/2-28 threading. Anyone restoring or cloning an HK416 upper will find this barrel cuts to the spec that platform was designed around.
This barrel is cut from 4150 steel and finished in black nitride, a salt-bath treatment that hardens the bore and exterior while resisting corrosion under hard use. The bore is button rifled with a 1:7 twist rate, which stabilizes the heavier 5.56 and .223 projectiles most shooters run today, including 62-grain through 77-grain loads. The medium profile keeps mass down compared to the heavier original contour without giving up the rigidity that matters under sustained fire. Muzzle threading is 1/2-28, the standard pitch for 5.56-class flash hiders, compensators, and suppressor mounts, so you can pair it with the muzzle devices and crush washers you already stock.
Builders working on an HK416 or MR556 clone use this barrel to match the original profile and chambering without sourcing a factory part. It drops into early-generation HK416 uppers and pairs with a mid-length gas system for a softer-shooting carbine. Once the barrel is installed, round out the build with the right gas block, bolt carrier group, and a quality cleaning routine. We carry the supporting rifle parts and cleaning gear to finish the job, along with a dedicated BRN-4 firing pin for the matching bolt assembly.
This barrel is built to HK416 and MR556 specifications and fits early-generation 416-pattern uppers. It mirrors the dimensions of the original factory barrel, which makes it a direct option for shooters cloning or restoring an HK416-style rifle in 5.56 NATO.
The bore is button rifled with a 1:7 twist rate. That stabilizes the full range of common 5.56 and .223 loads, including heavier 62-grain to 77-grain projectiles favored for duty and longer-range work.
The muzzle is threaded 1/2-28, the standard pitch for 5.56-class barrels. That covers most flash hiders, compensators, muzzle brakes, and suppressor mounts designed for the cartridge.
The medium contour is slimmer than the original 416 profile, which trims weight and helps balance the finished rifle. It keeps enough mass for rigidity under sustained fire while staying lighter than the heavy contour version.
It is cut from 4150 steel and finished in black nitride. The salt-bath nitride treatment hardens the bore and exterior surfaces and resists corrosion, holding up well under heavy round counts and field conditions.
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