I got a Winchester model 70, long action firing pin from a friend. It is brand new and unfit. It is the same dimension as a pre 64, including the safety cam surface, but it has the post 64 style firing pin retainer groove. Is this a very late pre 64 part or is this from a "Classic"?

If memory serves the post 64 and classic both have the C ring retainer for the mainspring. The pre-64 has the locking collar for the mainspring.

A photo says a thousand words.

This has the groove for the "C" ring and washer but has the large striker very similar to a pre 64.

I have never had a Classic apart, but most post 64 pins had smaller stikers; some had tabs for cocking indicators, grooves on the top striker surface for a cocking indicator and of course the ones for the pinned on cap.

The firing pin tip is smaller on the pre-64. A post-64 tip won't fit in the hole in a pre-64 bolt. Regards, Bill

What is the length of the pin, 9/32" dia and the small tip from the face of the cocking piece ( dry fire stop ) to the very tip of the small section.

That will tell if you have a
pre 64
post 64 long
post 64 medium
post 64 short

Jim Wisner