I had a baby eagle, which is a 75 pattern gun. I had it give me random failure to fire on hammer drop while still passing the pencil test. It had a bit of swarf from manufacturing left in the firing pin channel that was not very visible. Make sure your firing pin channel is clear.
I once tangled with a law firm "Fellon & Fellon" and could not take them seriously at all. Best line of all times ,when I couldn't get through Mrs. Fellon's thick skull was to tell her: Put your husband on the phone and I will explain it to him. hahaha she lost her mind!