Savage 24B-DL

I am attempting to find the date of manufacture for my 22-20 gauge over/under and I cannot find the serial # on it. What am I missing? The problem is that the 22 will not fire. The firing pin leaves an indentation on the rim of the shell but won't fire. The 20 gauge fires fine. Upon inspecting the firing pins while moving the selector switch it appears the 22 firing pin is shorter and beveled on one side. Is this normal for that pin?

Dang, never saw this question till now.

If your still around have a look on the barrel or receiver and see if you can find a small circle with a number and a letter stamped inside of it, it's a date code, then just get back to me.