If you have an infestation of giant critters that you'd would like to hunt at extreme range, I'd say go for it.
In all seriousness, are you going to be hunting very large game (elk/moose)? I don't have a RUM, but a quick look in the reloading book says that the RUM roughly equals a 300 WM + 200 ft/sec, its probably going to pack a wallop on both ends. In addition, at 90 - 110 grs of powder per pop, its going to be a hungry caliber to reload, and an expensive one to buy. That may not make a difference to you, but as a cheap SOB, thats the kind of stuff that runs through my mind.
just my $.02