I have a Bul Amory 9mm 1911 which was working fine until I had an optic cut and a Holosun 507 installed. I thought that the screw mounting the optic was reason that the pistol failed to eject because it was hitting the extractor, so I removed the mounting screw over the extractor, but I still had the problem of failure to eject. After loading one round in the magazine and bringing it to battery and firing the round the slide will not lock back using 115 grain 9mm ammo. I'm now thinking because of the added weight of the optic I need a lighter recoil spring. What do you think of this theory? If you agree that it is worth a try what strength of spring in pounds do you recommend that I try? Thanks