So my SN is B915XXX, the B prefix indicating a post 68 rifle IIRC. I found a table on the internet (not sure how accurate) that indicates a SN in my range prefixed with a B is a 1975 MFG date so the thread-on firing pin is suspect.
Its definitely a thread on - there is no accessible pin anywhere. There are markings on the outside of the firing pin that look like they were made with plier teeth. It's frustrating that I don't have the full history of this rifle, but at the same time its kind of a challenge and I enjoy that.
Unfortunately I don't have a box of parts to try and each offering on Numrich is pricey so I'm hoping to confirm a fit before placing an order. That may not be possible and I understand that.
Besides checking if the action improves, I believe a pin-on firing pin assembly is just more serviceable. I don't want to mark up the firing pin more than it already is to change out the hammer spring, for example.
