12 twist will do pretty much anything most people want to do with the 22-250 case. It is also the standard factory twist that Savage uses for it.

Personally I would either get a lightly used one from the classifieds here, or I'd order one from Jim at www.apachegunworks.com For the money you will get a much better barrel at a good price and probably quicker than ordering from most places (unless they just happen to have exactly what you want on the shelf).