Re: ar10 question
As stated before. Some do and some don't. A big difference is in the lower receiver near the extension tube. They are shaped diffently so that you can't put a DPMS upped on an Armalite Lower. You can actually put an Armalite upper on a DPMS lower but there would be a gap and it would look stupid. All the add on stuff, Buttstocks, forarms,, bolts, and triggers all interchange.