All that gun needs is a tightbore and metal hopup. I have one and completely stock it's out preforming everything else I have (with tightbores). Fires around (i'd guess didn't have the crony out at the field) 340-350fps. All I'm going to do to mine is add a tightbore. Also, M16's aren't for everyone. some people 6' tall find them too big but that being said, I'm about 5'6" and have zero issues using a full size M16.