Shooting a Noveske N4 Gen 2 lower with ArmaLite LPK.
20 round PMAGs just don't want to stay seated. 30 rounders are fine.
After a shot or two, the mag basically falls free and it takes a good wack to lock back up in place.
What can I take pictures of to help diagnose this?
ETA: The 20's seat with a barely audible 'click' when empty, and it's even less noticeable when they're full. The 30's have a positive / audible 'click' into place.