We’ve received a few inquiries about bolt rub on the ZMAG feedlips. This self-clearancing feature is by design. The key to magazine reliability is having the mags as high as possible in the gun, minimizing how far the bullet has to “jump up” into the chamber.
The bolt should be just “polishing” or slightly “scratching” the top edge of the feedlips, the bolt will self-clearance your ZMAGs to your specific gun(s) and be incredibly reliable—more reliable than any other magazine you’ve ever tried. (Don’t worry, the bolt is much harder than the metal used in the ZMAGs. The self-clearancing process won’t hurt your bolt.)
This is what a normal ZMAG looks like after self-clearancing to an M-11/NINE:
If the feedlips are stopping the bolt dead in its tracks, your gun is simply too far “out of spec” in some way. (Again, don’t worry, many are. With these inconsistent guns, everything is a matter of degrees.) Usually, removing a few thousandths from the top edge of your mag catch will resolve the problem.