Well, I tried a different shell stop, didn't help. I can't even manually cycle the action to clear shells from the magazine. The shell stop on the opposite side of the ejection port keeps stopping the feeding cycle. Is this cam that you mention part of the barrel extension, if that is called the action bar? Or is there a part of the bolt body that is supposed to hold the shell stop out of the way? It seems like if it were on the barrel extension, that it would only hold the stop out of the way if the action cycled under recoil, sending the barrel back in the receiver to operate the stop, but, you wouldn't be able to manually cycle the action to clear the magazine. That doesn't sound quite right. If it were on the bolt body it should work if operating under recoil or manually, as the bolt and the barrel recoil then unlock, then release the shell stop to allow only one shell to enter from the magazine. Or am I way off base? I may try the bolt from the project gun, once I can get all of the crud cleaned off of it. Or, I may compare dimensions of the 2 bolt bodies for the rib that rides in the slot over the shell stop. If you have any other ideas I'd love to hear them. Thanks