Well my plans for the ASA side charge upper are shot out of the water. I called them today and the rep said that there NONE of their uppers are compatible with DPMS ( I thought I read it was somewheres for sure ). He said that their uppers are based off the armalite, and their side charge was only compatible on THEIR lowers. So there it is, who knows different? I am now sad over this for the fact that the ASA side charge upper is just so dang good looking and made of quality. :'(