So i finally got around to swapping out and adding my plus 1's but now it seems like the gen 4 plus 1's lip needs to be sanded down some, the magazine won't fully seat in. Seems like the gen 4 lips are not slanted enough compared to my gen 3 ones. Anyone ever had this problem before? And yes my gun is a Gen4 so i'm assuming the mags that came with it are gen 4's too.