Are the tikka wsm and standard magnum magazines interchangeable? Are the magazine well in these rifles the same size? I know the 308win mags click right in to my .223rem. I want to build a 7saum on a tikka action and want to know what doner rifle to purchase. Any magnum action or will it have to be a wsm rifle? Am I correct in assuming that Tikka uses the same length action for all cartriges?