Hey, just got my RAP4 stock, it says it's for the 98c, but it doesn't fit. First I had to drill the holes for the springs a bit as they were too small, and now when I try to close up the gun it won't close all the way, it's too thick in diameter. Has anyone else had this problem? What should I do? Should I try filing it down more, or do I just need to push even harder?