Are your 308 lowers Mil-Spec?

This is a loaded question, as none of the Armalite AR-10 models were adopted by DoD/military, so there wouldn't be a mil-spec. Our SR25 / ar 10 lower has been modeled after the Armalite AR 10A model. This profile is standard on all AR-10 profile rifles and lowers, such as the SR25 rifle. We purchased a DPMS Gen-1 LR-30880 80 lower receiver and reverse-engineered it. Our lowers fit perfectly with their upper, and our upper matches they're lower. Although there is no specific mil-spec for 308 AR-10 models, we machine billet aluminum lowers to tighter tolerances than the typical shop tolerances, which are +/-0.005'. We machine the lower complete, including faces, to tighter tolerances. AR-10 308 80 Percent Lowers the Legal To Own and Build Yes. According to the Gun Control Act of 1968, it is legal to construct your firearm for personal use in any state in the U.S. as long as you are legally allowed to own a firearm. New Jersey, for example, has "Assault Weapons...