Brownells BRN-4A(R) 10.4" Medium Barrel Upper Receiver Build Kit

Build your own upper receiver kit! The BRN-4A(R) is now available as an Build Kit. Simply add your preferred HKA(R) 416 compatible handguard and any 1/2-28 muzzle device, and you're ready to build! Includes all of the main components, plus a BRN-4A(R) barrel nut wrench to properly install the barrel. The core of the BRN-4A(R) Upper Receiver is an all new Bolt Carrier Group, featuring a slick nitride finish. The carrier itself is machined from one piece of forged 8620 steel. The bolt is precision machined from 9310 tool steel and headspaced prior to and after barrel installation. The new BRN-4A(R) barrel, produced by FaxonA(R), is available in a variety of p Mfg: Brownells Bundles