Wink: your 348 gr. power belt bullet should be good enough, provided you have a round nose or flat nose( semiwadcutter) profile. You don't want an expanding bullet on these heavy boned animals. 350 grains of lead is a lot of lead moving down the way. It doesn't have to go very fast to keep on going when it hits flesh. You are shooting a light .50-90 load, but those guns killed a lot of elk, and buffalo. If your load is accurate, use it. You can always do penetration tests, and range tests to see if you want to increase the load. The Old Mountainman, Jim Bridge had a powder measure that threw 50 grains of powder. He told a biographer that he use one measure in his .54 hawken for shooting deer and antelope; 2 measures for mountain lions, Elk, and black bear, and 3 measures for grizzley bear. I doubt many experienced shooters and hunters could argue much with his choice of loads. Line that load up so it breaks a foreleg either coming or going into the lungs, or heart, and you should have your elk. If it is close enough, shoot him in the neck where it connects to the shoulders and give the largest target for hitting the vertebrae.