Scott,
Actually, the case capacity of the .35 Remington and .358 Winchester isn't all that different, around 12% with a 200-grain Hornady RN seated to the cannelure. This translates into about 100 fps difference with 200's WHEN BOTH CASES ARE LOADED TO THE SAME PRESSURE.
However, I sure as hell wouldn't do that with anything except a bolt-action .35 Remington. Pressure is the big difference between the two rounds, not case capacity.
