From memory a great book on Mausers and modern rifles based on the 98 action is by Jerry Kuhaunsen (sp?) it is, or certainly was until recently available from Brownells.
I think the Title was Mauser 98- "A Workshop Manual"- covers all aspect of gunsmiting these actions including hardness valiues and opening out the action for length of cartridge and the bolt face for larger head sized cases, if you are serious about using a 98 action then seek a copy of this book.
I have two custom rifles built on M 98 czech vz 24 actions. A 7x57 mauser and a 6.5 -06 .Both rifles are highly accurate . Some advice, I would stay away from using turkish mausers, 94 mausers actions , 95 mausers actions, spanish mauser actions. I would use M98 mauser actions to build a custom rifle.With my 6.5-06 I can hit shooting clays out to 500 yds with it.I would also buy the Mauser Bolt Action book by Jerry Kuhnhausen for reference.Goodluck