You've got to real careful installing the spring. Part of the spring might caught I believe ,behind the leafs of the spring. If it`s a colt grip safety It should fit. The trigger bar must remain free & outside of the grip safety . A grip safety can be carefully installed with .030 is the maximum to mill off the grip safety . I however wouldn`t take that much off. My feeling is that you haven`t got the safety spring correctly. IMHO Chas.