I'm looking to do the staggered feed to center feed internal magazine change for a saum build on a 110 action. I see on Savage's website that there are 4 long action mag types. 30-06, 7mm rem mag, and 300 win mag, and the RUM's. For a saum build, I'm thinking the 300 win mag magazine would be the choice, with some tweaks. Can someone explain the differences between the 7mm rem mag and 300 win mag center feed magazines and which one would be the better one to go off of?