Very good points to bring up Cayugad.

I've never experienced any freezing of a firing pin. But then again, I don't hunt extremely cold weather. In the teens is about as low as I see it buy normally not below the mid 20s.

I think that's why several people I know keep a hand warmer on the action of their guns. I think Jim Shockey is one that does it as well.

As for charges slipping. I always check it when I get to the stand. I've never had one slip but I still check it every time. It only takes a second to do it, and it could save you a lot of stress in the long run.