My 37 wont load shells from the magazine. First chambered shell fires, I pump hard and the spent round ejects no problem, but it wont pull another round from the magazine. Any suggestions? I notice that the shell stop doesn't seem to be working (moving out of the way to release another shell) I took it apart and cleaned it (I thought that there might have been some dirt preventing proper action). It still doesn't eject. Every now and again it will, but rarely. the left shell stop is retained inside the left wall of the receiver by a small vertical screw in the older models which is what I have. It's this shell stop that's causing me problems. Is this tiny screw supposed to be set just so? I just tightened it. After I reassembled the gun, it worked again, for a short while, then same problem.
Thanks for any advice.