I finally got my 10FCP McMillan build up and running

So decided I'd get the old 10FP converted to a .223, and right off the bat ran into a problem.
The tail on the bolt doesn't let the firing pin assy in far enough. It hits the collar. The tail piece looks like it has a good 1/8" longer behind the retaining pin hole. other difference is it has a small slot milled in the ejector port side of the tail, not sure if that means anything or not.
Is this a matter of adjusting the protrusion of the firing pin? or is it a bigger difference between the firing pins assy's?
I"ll get some pics up later

thanks in advance