While testing at Aberdeen we engraved a number on each mag and if there was a stoppage it was identified as to type, its location ( say 7th shot in mag) and recorded. All magazines were run through all weapons. If that mag gave same stoppage in same or other rifles it was removed and crushed.

It is critical in a defensive application to know your rig is reliable.

If you have high round mags examine the back of the mag for cracks at angle where feed lips interface with back of mag.