Description These Tromix built AR-15 450 Bushmaster Economy uppers include the exact same new Premier Grade Tromix BCG’s and 18″ Lightweight Barrels just like the Tromix standard lineup of custom uppers, however, the charging handles, 15″ hand guards, and upper receivers are made from less expensive 6061 aluminum instead of 7075. Gas blocks are steel, .750″ diameter, solid, non-skeletonized. Barrels are 1:24 twist 4150 steel, mid-length gas system, 5/8-24 muzzle thread, with an A2 style bird cage flash hider installed. All of the Economy uppers are pre-assembled so no optional or alternate parts can be spec’d out. These uppers are test fired for proper functioning prior to shipping. Some parts may have minor blemishes. Upper weight – 4.0 pounds. Total rifle weight w/std M4 stocked lower – 6.05 pounds SB 704 applies to all California sales – Must ship to FFL.
