Originally posted by sns3guppy:
The P320 mags can sometimes be difficult to seat if they're fully loaded.
I've seen several shooters at meets drop a magazine at the start of a stage. The magazine appeared seated, but the jarring from recoil caused it to drop from the weapon after one or two shots.
I've also found that it's not that hard to press the mag release. There's a product that I put on each of my competition pistols, made by Align Tactical.
https://www.aligntactical.comIt repositions the contact surface of the mag release, moving it upward slightly, to prevent the fingers of the shooting hand from looping around the front strap and resting against the mag release. It also makes the mag release easier to press with the thumb, without it being inadvertently depressed.
Unfortunately, they don't make it for the .45.
It is possible, depending on the size of your hand, to contact the mag release with the fingers of the shooting hand. It's also possible depending on what holster arrangement that you use, to depress the mag release when holstered, holstering or drawing. It may be just enough to allow the mag to move.
Something I might suggest would be locking the slide back and inserting the magazine. See if the problem persists. If it doesn't, then most likely the magazine isn't being fully seated on insertion. You might also try running it with one less round loaded in the magazine and see if the problem goes away; if this works, it points to the same issue: the mag not being fully seated and fully locking in place.