Those guns do have a firing pin stop but with wear and battering the pin can protrude too far. The bolt has a countersunk area that encloses the case rim; the non-countersunk part of the bolt face butts up against the barrel face and the firing pin should not protrude past the end of that countersunk area; it should stop in the countersunk area so it never touches the barrel.
A quick and dirty fix is just to grind a bit off the front of the pin so it doesn't protrude beyond the countersunk area. That is a pretty old gun and probably just about everything is worn; might I suggest retiring it and getting a more modern plinker, like the Ruger 10/22.
(I am not sure how well I explained that, but I don't do drawings well. If still unclear, I will try again.)