I'm also experimenting with modifying some M&P mags and CZ mags to employ while in the carbine. You need to Slash the notch inside the front in the mag so it will lock in. I do not have any Glocks. I would use Glock branded Publications and not another copies. https://paxtonfiheb.blogocial.com/5-essential-elements-for-ruger-shotguns-68041993