First they are junk and will not work. Had to pry them out of the gun. This for a mag thet I told them in my order letter to send "if they would work well" in the Sistma I ordered. Well, neither the gun or the mags were anything to brag about. Last night I took my Leatherman file and opened up the mag catch slot on them and stretched the soring. Now they can be pulled out and sometimes even drop free on their own. I think with a new follower and spring they would work good. If not addiong a new mag body and floor plate would sure fix them.BTW, these are 10 rnd mags. Don't buy them, but if you already have try this to make a plinking mag.