I purchased 6 Magpul Glock mags and have run them in my Gen 1 and 2 Sub2K's. Two of them have had issues right off the bat with the follower tilting and becoming stuck midway in the mag. I've had to empty the mags and use a screwdriver to get the follower unstuck. Spoke with the LGS where I purchased them and a salesman said he and his friend encountered the same problem. No issue with them being too tight in the magwell but I'm sadly getting better results with my el-cheapo KCI mags.