Mr. Steinmayer's advice is correct.  The action is a Krag, not something chambered for .308 or .358.  40.0 grains of IMR 4350 pushes a 220 grain jacketed .30 cal bullet at something approaching the velocity of the original Krag cartridge. 

If you use the same 40 grain load in a Krag case opened to .35 caliber, and you are pushing a 220 grain bullet, the peak pressure will be about the same, but pressures will drop quicker because the gas is escaping from a tube that has a bore cavity of greater capacity.