My 6-rd mag seems to work fine. I got about 150 rounds through it. The plastic baseplate is solid and does not move. A metal notch in the middle of the plastic seems to hold it in place just fine. I have to pay close attention that it locks in the gun. With ear protection I can't hear it click in place. Couple of times it was not seated and slid out of the gun. My 8-rd mag baseplate does slip if I use my loader. The pressure pushes the plastic upward. I just use my thumb and slide it down so it can lock in the gun. Not sure if I will call Sig and ask for a replacement. Think they are probably all that way based on the design. No issues loading the 8-rd mag with two hands and my thumb. Except the last two rounds get tight to push in.