I have taken my model 41 bolt appart. I also checked the holes in a new one.

The holes for the firing pin and extactor and spring were gritty or rough inside on both. So I polished the entire bolts. Now the firing pin and the extractor feel smooth as glass when moving on both.

But then again I'm an ex toolmaker and I look for operations that I would have done.

+1 on the wolf spring kit.