I have a styer-solothurn 98 mauser from 1934 that was sent to Columbia as a 7x57, bought back by Israel and rebarreled to 7.62x51, imported to the US prior to '68. Very well done "economy" sporterized (military stock cut down, glass bedded, barrel shortened and an M1carbine front sight installed with a Redfield apeture receiver sight).  It presently has an FN bolt, and works fine save for one bothersome problem.  A cartridge will not stay on the bolt face until it contacts the ejector...about 50%+ of the time, it simply falls off as soon as the cartridge clears the chamber.  Extraction works fine.

From what I understand, a loaded cartridge should stay on the bolt face, let alone an empty one.  Apparently there should be a small (like 0.001-0.002) "nub" on the bolt face rim next to the ejector slot that holds the cartridge until it contacts the ejector.

Not having a TIG welder or a lathe, I opted to order a stripped bolt (for the proper receiver) from Numrich and a new extractor, along with a Field chamber gauge.

Question is:  What are the odds that this "new" bolt will properly headspace?  I know, I won't know until I try it, but any of y'all that have swapped bolts in '98 mausers, what's been your experience?

After that many years and variables, it will need to be looked at closely.  

Are you sure the extractor was not wore?