My model 648 (22MRF) misfires. It dents the primer about .004", am told it should dent 012". Strain screw is tight, not the problem. Misfires worse with CCI ammo, does best with Aguila, but still misfires 20% of the time. Anyone had firing pin problems with Mdl 648 or Mdl 617? It shot fine for 20 yrs, set up unfired for 5 yrs, now it misfires way too often to be reliable. Could it have the wrong (too short) firing pin? Nothing has been altered or monkeyed with, I bought it new. Could old oil be in firing pin channel?
Thanks in advance for any help or ideas.
blueticker