Great grip but not the best fit - Bravo Company MFG Gunfighter Grip Mod 3

This is my favorite grip out there, I prefer it over the Magpul k2, both are good of course. However, this grip would not full seat in my Matrix lower reciever out of the box. After about an hour of filing away some of the internal walls of the grip, it almost fit just right. Could be my lower, could be the grip. But my K2 and MOE went right onto the same lower, no modifications necessary. This can happen