I was offered a model 12 stainless with laminated stock in 204 Ruger at a good price. I have no use for the caliber, so thought about picking it up and converting. I'd like to do a 6mm Creedmoor build. I know a bolt head replacement is needed, but what about the magazine? Is it a simple follower change or is it a completely different mag box? I suppose I could always just do a single shot conversion, or do something simple like a 6X45, but I'd like something a little more capable on game in the deer/black bear class. Thanks.