Don't have the numbers here but the 243 uses a standard bolt face. That means most of the standard cartridges(non-magnum) are the same size, 30-06, 308, 358, 260, 7x57, 8x57, etc... The magnums obviously use a larger bolt face while the 222, 223, 17 Rem etc. use the small bolt face. The action sill also limit somewhat you cartridge choices. Short actions such as a 243 in the M700 will be put up in a short version of the m700 action and calibers such as the 270 would not work. Of course that's pretty much achedemic as almost any power level can be accessed in the short action. The 22-250 or 220 swift for varmits, the 243, 308 for general medium game and the 358 and new 338 Federal for larger animals..