SKU: 80001441
UPC: 050806500723
MPN: BN-BRN4556-14.5
The Brownells BRN-4 14.5'' heavy profile barrel is a 5.56x45mm NATO replacement and build barrel cut for HK416-pattern upper receivers. Manufactured by Faxon, it follows the dimensions of the original HK416 barrels closely enough to drop into early-generation uppers and BRN-4 components. Shooters building or restoring a 416-pattern rifle get a 14.5-inch heavy contour with a 1-7 twist that stabilizes the full range of 5.56 loads, including heavier match and defensive projectiles. The 1/2-28 muzzle threads accept standard AR-pattern flash hiders, brakes, and suppressor mounts, so the front end stays familiar even on a piston gun.
The barrel is forged and machined from steel and finished in black nitride, a treatment that resists corrosion and wipes clean without the chipping you see on coated bores. Rifling is button cut at a 1-7 twist, the same rate used across most modern 5.56 builds, paired with the 416-length piston gas system this platform was designed around. The heavy profile adds mass under the handguard, which steadies the muzzle during strings of fire and slows heat buildup compared to lighter government contours. At 2.45 lbs per manufacturer specifications, it carries enough material to stay rigid without turning the rifle into a bench gun. Builders pairing this barrel with the right gas hardware will find our selection of rifle parts useful for completing the assembly.
This barrel makes sense for anyone running an HK416, HK MR556, or a BRN-4 build who wants a heavy contour without sourcing factory European parts. It suits range work, precision practice, and duty-style setups where a stiffer barrel holds zero through sustained fire. Confirm your gas system and bolt are 416-pattern before ordering, since this is not a direct-impingement AR-15 barrel. Once the barrel is set, keep the bore in shape with our cleaning supplies, and finish the muzzle with a crush washer or flash hider sized to the 1/2-28 threads.
It is built for HK416-pattern upper receivers, including the HK416, HK MR556, and BRN-4 component builds. It uses the 416-length piston gas system, so it is not a drop-in replacement for direct-impingement AR-15 uppers. Confirm your gas hardware and bolt are 416-pattern before ordering.
The barrel is button rifled with a 1-7 inch twist. That rate stabilizes the full range of 5.56x45mm NATO loads, from lighter 55-grain rounds up through heavier 75 to 77-grain match and defensive projectiles, which is why most modern 5.56 builds use it.
The heavy profile adds steel mass under the handguard. That extra material keeps the muzzle steadier during sustained fire and slows heat buildup compared to a thinner government contour. At 2.45 lbs it stays rigid for precision work without making the rifle excessively front-heavy.
The 1/2-28 muzzle threads are the standard pitch for 5.56 AR-pattern rifles, so common flash hiders, muzzle brakes, and compatible suppressor mounts thread on directly. Pair the threads with an appropriately sized crush washer for proper timing.
It carries a black nitride finish applied over forged and machined steel. Nitride resists corrosion, holds up under heat, and wipes clean during maintenance without the chipping or flaking that can affect some external coatings.
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