Brownells BRN-601 5.56MM 20'' BBL UPPER RECEIVER NONE

The BRN-601® Complete Upper Receiver is back!   Styled after the original Model 601, introduced in the late 1950s, the BRN-601® has distinct features, only found on those early AR-15 rifles. Starting at the muzzle, the "duckbill" flash hider is retained by a proper split washer of the proper size. The flash hider is attached to a lightweight 20 inch barrel, found on AR-15 variants through the M16A1. The 1-12 twist stabilizes 55gr and lighter projectiles extremely well, while the 20 inch barrel provides plenty of velocity. The front sight base is not F-marked, meaning the round, tapered front sight post is properly in line with the carry handle rear sight. Solid green triangle handguards closely emulate the original green painted handguards found on the 601. A flat slip ring anodized matte gray is at the end of the 5.56x45mm NATO barrel assembly.   The upper receiver matches the slip ring anodizing, in a beautiful matte gray. Mounted to the upper is a proper ejection port cover, with a flat external "bump" (not just an off the shelf A2). The triangle charging handle also has the same anodizing, giving the entire assembly a clean look. Inside, you'll find a chrome bolt carrier group quite similar to the original. It even has the solid firing pin retaining pin! These do have modern staked gas key screws and a modern firing pin (unlike the old large style firing pin). The front pivot pin hole is recessed to funciton with the 601 pivot pin. The A1 type rear sight assembly is right at home in the slickside upper receiver as well.   Key features of the BRN-601®: Slickside upper receiver Matte gray anodizing (not painted) 20" 5.56x45mm NATO barrel with 1-12 twist & chrome bore Chrome, slickside M16 bolt carrier group with 9310 bolt Duckbill three prong flash hider