[Seano]

I had one of those Harrington pins in a '52 I used to have. Major improvement over the brittle issue ones, those have been well known failure points for many many years now. Yeah, did you check for dried Cosmoline down in the firing pin chamber ? Sometimes that stuff is really hard to see and remove, and it can build up right where the front end of the pin goes through it's little hole like hardened super-glue, preventing the pin from traveling quite as far as it needs to in order to really thwack a hard primer good. Heat is the best way to get that Cosmo out of Com-Block surplus, I've found. Boil it in water if you have to and/or heat it with a blow dryer, and thoroughly bathe in CLP...you would be amazed at what comes out of the little nooks and crannies.

If I still shot my CZ-52s I'd buy another Harrington pin in a heartbeat, but I switched to a couple of TT-33s for shooting 7.62x25...small hands.