I have a Colt 70 series I bought new when they first came out. I removed the recoil spring guide and replaced it with a spring loaded shock absorber much like what is available from Kings gun works. The gun functioned flawlesly for many years and through multiple spring replacements. The buffer finally broke. I replaced it at the same time I changed out the springs. Now on the last round, the case does not fully eject and it gets caught by the slide on the upper quarter of the case mouth ripping it and attempting to stuff the base of the case back into the magazine. The gun is jammed with an empty case. Does anyone have any foggy idea what is causing this and why? At about the same time I noted a hairline crack in the frame forward of the slide stop pin on the left side. I really do not think one has anything to do with the other, but who knows in the violent recoil action. Fexing may just be the culprit causing the slide to operate at a different speed. At any rate it has been returned to Colt for repairs, so I do not have it in front of me.