I just sent in my Axis to CDI, as always, inletting services are free (and quick). I can only comment on Alpha Industries mags, and MDT polymer mags as they are all I have. Accuracy International mags are too pricey for me. The MDT is ok, seems to feed ok, but no room for longer bullet seating. The mag is pretty close to touching factory ammo. My choice of the two is the Alpha. It's way shorter (double stack as opposed to single) and has room for longer OAL. In fact Alpha offers a mag with a bit more clearance than the one I have. I can't wait to get my mitts on the Magpul AICS mag, that is IF they ever release them.