Have a mid 70's gun that has sentimental value.

It will not shoot more than once and the second shell hangs up before it gets to the chamber. Light loads or heavy... does not matter.

Replaced the recoil spring in the stock. Taken apart the entire gun and cleaned. Gas ports are open. O ring is fine. Light lube. Chamber has been scotchbrited. Magazine spring looks good as does the tube.

What am I missing?

I put TWO o rings on it just now and will see if that makes a difference tomorrow.

If I can't get it running, who is the guru to take it to?