Quote Originally Posted by jmart View Post
There's a whole history of where BM, RRA, etc. fall short on several items on this list, but where do they fall WRT gas port diameters? Are they spec? If not, how much over or under?

Not even close. They all use LARGE gas ports (.068-.073). Reason? Because they expect their customers to use the cheapest (read under pressured) ammo they can find and they don't want to get complaints about their AR's not cycling. The issue is that when their customers DO use Mil-Spec pressured ammo, they are beating the guns to death (breaking bolts, bolt override, hard recoil, etc).


C4