I bought a smith and wesson 4006 and have a failure to feed on the last round. The round is slammed against the entrance of the chamber and slammed by the slide. I tried changing recoil spring along with oem springs then with wolf springs. Havent tried it with wolf springs yet. I just wonder if the yellow followers i have are different from the present blue followers. What seems to be helping is tweaking the feed lips making them narrower. I hope someone here helps me with this problem. I am new to the forum thank you.