Please dont take this as a flame, because it isnt. Im asking out of sheer curiosity. If you were already buying an action for a planed build, why not buy a magnum action to begin with?

I know I have had a few naked actions laying around, none of witch were Magnum actions. I flirted with the idea of making one into a magnum single shooter for the range. Even making one into a repeater. The advice my smith gave me was although it can be done, you'll be happier/better off starting with a magnum action From the start. Cost wise and peace of mind goes a long way.