Bryan, 6.5-'06 or .280 Rem will do it with no changes to the bolt face or magazine. I don't remember if the '03 bridge needs any reshaping, (03-A3's need a little). The bolt handle has to be forged down or cut off and rewelded / reshaped for scope clearance and a low scope safety installed. The case hardening on the receiver has to be broken in the spots where you drill and tap for scope bases, but there are a couple of common methods for doing it. Also, the barrel tenon has a square form thread that is a little slower to cut, and a cone breech that's a little trickier to headspace.
These receivers blue beautifully and make strong, good-looking rifles. Be sure they are the "high number" receivers.
A good plan for a fine action, Tom
Texas State Rifle Association Life Member
NRA Endowment Life Member
A big fast bullet will beat a little fast bullet every time