I know ive put this on before but i'll try it again. My buddy has a 9mm abd the follower is hanging in the cut out on the mag. I put this on before and was told to make sure they were clean, we cleaned them very well and oiled them up but the problem persisted. This is the second set of mags hes had, the gun shop gave him 2 more when the others started with this problem. Now the new ones are doing it, they have about 400 rounds through them when it starts to hang up. Any help would be greatly appreciated, thanks.