I was trying to find some new magazines for my AT-84. I purchased a new Mec-Gar CZ-75 magazine (16 rounder) to see if it would work in my pistol. The magazine fits tight but went in and locked into place. It functioned good in the pistol. No jams and the slidelocks back when the magazine is empty. So if anyone is wondering, the Mec-Gar magazines are compatable with the Action Arms AT-84.