I am also experimenting with modifying some M&P mags and CZ mags to utilize within the carbine. You need to Lower the notch while in the front in the mag so it's going to lock in. I don't personal any Glocks. When you purchase by means of links on our https://rugerp89forsale45666.free-blogz.com/79499111/ruger-sr45-for-sale-an-overview