Re: Action size??
You can do a singleshot RUM on a savage action with no problems at all. Things get a little cramped if you want to mag feed ammo. any of the cataloged items chambered for 300WM will work, and you need a RUM/wsm bolt head... $17 from midway. numerous folks do drop in RUM barrels for savage actions, and rum barrels are still avalable from savage. The barrels from savage are built for the large shank actions... most of the aftermarket barrles can be had either way. Numerous rifles chambered for 300RUM, and the lazzaroin cartridges came from the factory on small shank actions... so no fear of building one on the small shank.
Its your money, and your perrogative on how you ballance all the issues of accuracy per$, resale value, astetics, stock options ect...
but for my $ Savage all the bay baby!