Check rim thickness, too, as I believe the rim thickness on the 9,3x57R/.360 is thicker than the rim on the 9,3x72R. At least, in most cases...

This is the .360, I believe, carried by Nansen on his great trek during the now-famous and still utterly amazing "Farthest North" expedition. His expedition can really only be compared to a lunar expedition of today. Indeed, it was more difficult in some ways, as he had no contact with the outside world for over two years.

Muzzle velocities in a rifle are similar to what are generated by the .357 Magnum in a handgun; about 1400-1500 fps with a 150 to 160 grain bullet IIRC. Nansen rouytinely used this combination on Polar Bear with good success. His Cape Guns had 20 bore shtgun barrels and he did bring slugs of some type {probably round ball} loads for the 20 bore.

Tho ballistics do not say "Polar Bear" to us today, his choice of gun, like all equipment, was very well thought out. Remember, all gear had to be dragged by sled, pulled by dogs or man, so weight of ammunition was VERY important. 20 bore guns killed bird life well, and the rifle handled seals and other mammal life as well. Amazing man. Amazing trek. Certainly in the great tradition of the Norse explorers of the Viking era.