Description These Tromix built AR-15 450 Bushmaster Economy uppers include the exact same new Premier Grade Tromix BCG’s and 12.5″ Lightweight Barrels just like the Tromix standard lineup of custom uppers, however, the charging handles, 10″ hand guards, and upper receivers are made from less expensive 6061 aluminum instead of 7075. Economy .750″ adjustable gas block is included and one M-lok slot on the hand guard has been modified to allow clearance for adjustment . Barrels are 1:20 twist 4150 steel, carbine length gas system, 5/8-24 muzzle thread, with an A2 style birdcage flash hider installed. This particular upper is set up to run subsonic ammunition, but can also be used for full power ammo with the gas block turned all the way down. 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 – 3.34 pounds. Total rifle weight w/std M4 stocked lower – 5.39 pounds SB 704 applies to all California sales – Must ship to FFL.
