6061-T6 or 7075-T6: Pros, Cons, and Decisions By Brian McCombie

6061-T6 or 7075-T6

Those of us who build our own AR’s invariably come across the debate: should I use upper and lower receivers made from 6061-T6 or 7075-T6 aluminum? For many, it’s a no brainer. 7075-T6, right, because 7075-T6 is mil-spec for M4 Carbine uppers and lowers, as determined by the U.S. Military. Right? Not so fast. While 7075-T6 has … Read more