The barrel in the rifle wouldn't really need to be changed. It can be reamed to 22-250 with out taking it out of the action. The rest of the job is not really very difficult if you purchase a new magazine box, spring and follower that problem is solved. The boltface opening will be the more difficult part as there will be extractor issues to be addressed, but these are not insurmountable problems for a gunsmith or a machinist that has some gun familiarity. The whole job should come in at about half the price of a new rifle.