You may be having trouble finding a .54 because the trend now is to use sabots with smaller cal. bullets. This is an easy way to make a ML shoot faster and flatter. If you load a .45 of .50 cal with a sabot you can get up to 2600fps which is more than twice what I can get with conicals. In some states it's legal to shoot a ML with a scope,add that to a modern in-line and you basically have a modern rifle. Alot of people use a ML because they want to hunt longer seasons with more chance of success, but they don't want the handicap of a ML.

If you look hard enough you'll find a .54 if that's what you want. I even saw a guy using a hawken style .68 cal ML....what a beast!

And yes a .50 is adequate,but that's the smallest you can shoot for elk in Wa. I just like to be able to really hammer whatever I shoot at.