Okay,
I know that this is a very old thread. But I recently came into a very nice AT-84S that shoots very exceptionally. After 8-10 mags, I noticed that the magazine (I have two factory original mags) would drop out of the frame just enough to cause the slide to miss picking up the next round. Further checking revealed that the very slightest pressure on the mag release was all that was needed to do this.
So I checked the mag catch with the top end removed and the part that locks the mag in is only slightly visible in the mag well. While very slightly pushing in the mag button, from right to left, just a bit more protrudes into the well and the mag is fairly secure. So I pulled the release spring and “modified” it, allowing more pressure on the button, pushing it to the left. So far, so good.
All that said, should I be looking to CZ (original 75) or Tanfoglio for a backup mag catch and spring? Or any other parts for that matter? Thanks.