to build a 9mm, there's 2 styles.Hey everyone with the know-how. I have in my posession a built AR dmps lower w/grip and M4 kinda stock. I've been looking at uppers and ($$$$) I've been thinking about a 9mm. Whats the process with those? I have to install some kinda mag adapter right? And more than likely get a SBR tag? Is it worth the pain, I already have a 995.
the olympic arms style which requires 2 holes to be drilled in the upper to mount an ejector and the colt/rra style which has the ejector in the mag block.
you will need to swap barrels and get a 9mm bolt carrier group.
i prefer the olympic arms style since it can use unmodded sten mags with a mag block. the colt/rra setup requires more tuning from what i've read and the mags are more expensive.
no sbr stamp unless you plan on having a barrel shorter than 16".