Brownells says to watch out for some anomilies:
http://www.brownells.com/aspx/NS/GunTech/NewsletterArchive.aspx?p=0&t=2&i=348
But I have a receiver and barrel I pulled from it they do not describe.
Major thread diameter = .977"
shank = .714"
Pitch = 12 tpi

No small ring barrel is going to fit that barrel without some modifcations to the barrel or receiver.
When I try to screw small ring barrels onto it, the theads are too tight, and the barrel shank is not long enough.

Welcome to the world of Turkish Mausers/. The 1903's nominally have .980"x12 tpi threads and the shanks nominally are .705" long.

That said, I've yet to come accross a standard 98 whose shank was the nominal .625" in length.

I've got a Turk that is .980" 11 1/2tpi.

The Turks started with 93 small ring actions. When 98's came out they ordered them with 93 threads to use spare parts. As time went on they used oversize threads when rebarreling to kep the joint tight (some small ring actions would stretch a bit). Finally I have heard of a tapered thread (like a pipe) being used. You have to measure each one to tell what you have.
Good luck1