Looking around, I don't see many benchrest games being won with Mauser actions. Seems like with feeding less of an issue, and the low cost of the base action, it would be a great way to get into a precision long-range gun.
Do the regular stuff, true/bed, chamber in PPC or something, target barrel and go, for under $600.
Is it difficult to get a Mauser to go sub-MOA?

Its not difficult to get a Mauser to sub MOA. But to be competitive in benchrest games it'll take sub 1/4 MOA.

In essence the Mauser action is just too flexible to get to that level of accuracy. And thats why Mausers dont make the playing field.

Like Ray said, MOA is easy, even 1/2 moa in a Mauser, but that won't win a benchrest match. What is funny is the guy's that think what is the best benchrest rifle, is also the best biggame rifle.