We don't classify the .30-40 Krag as a small bore cartridge today, but when the U.S. Government dropped the .45-70in 1892 and adopted the .30-40 it is easy to see why "it" was once considered a small caliber. As is usually the case with U.S. Military cartridges, the .30-40 enjoyed a great deal of popularity as a big game cartridge long after it had been replaced with the .30-03 in 1903. And for good reason; ballistically, the .30-40 Krag and later the .300 Savage are practically identical. Of course, the availability of war surplus Krag-Jorgensen rifles to civilian shooters for $1.50 didn't hurt the .30-40's popularity either. One seldom sees a big game hunter toting a .30-40 Krag in the woods these days but that has nothing to do with its performance. Even today the old cartridge will hold its own with a number of modern day wonders and even is superior to some. A 150 grain bullet at 2500 fps is strong deer medicine and a 180 grain bullet at about 2300 fps would be fine for elk and moose out to �150 yards or so. A number of propellants work fine in the .30-40 Krag with H414, H380, H4895, IMR-4320, and W-760leading the pack. 

This text is based on information from “Cartridges of the World”, Hodgdon reloading manual, the cartridge designer and/or own resources.