So, I was out making brass yesterday when I grabbed the M&P and slid a magazine into place. It was awfully loose for some reason. Well I also had my new cz75b along. Turns out I had a 75b magazine in my pocket while shooting my M&P. So, it ran all 16 rounds just fine then actuated the slide hold open as well. I wouldn't do it as a matter of regular habit. It is awfully loose fitting and there is about a 1/4" gap at the grip. The M&P is too wide to fit the magwell of the 75b. Ammo was all fmj. Much distruction was went on helpless steel targets.
The End.
The End.