I saw an interesting article on FB yesterday, It was written about a gun range in Las Vegas or Nevada that run full autos. Said some of their guns have 200,000 round down them. they said never had a upper or lower fail. just BCGs and barrel lugs so unless you are going to be shooting more or jumping out of planes ect. I have a billet lower on my main gun just because of looks a little better. built in mag well extension, trigger guard ect. shoots just the same as my $129 PSA complete lowers. Just try and find upper and lower with a close fit and you should be good.