Thanks to all of you that took the time to respond.

I have 54 cal Thunderhawks which I consider a wonderful gun especially when converted to the 209 primer...only problem is the breach plug is not removable for easy cleaning. My favorite load is the Barnes X 50 cal bullet in a 54 cal sabot and 90 grains Pyrodex Pistol powder (FFF)...great elk round everywhere but Colorado where I use the large REAL bullets and the same powder charge...FFF because of the short barrel on the Thunderhawks.

Last year I hunted with a friend who bought a new inline 50 cal mostly because that's all the dealers had on their shelves. We had a hard time finding a decent bullet that met Colorado's bullet restrictions 2x cal and settled on the heaviest powerbelt hollow pt because the aerotip is too long. Two solid hits on a 5x5, first in the shoulder, 2nd in the lungs and we didn't recover the animal. That experience again convinced me the 54 cal is best elk option at least for Colorado or any other state that prohibits saboted bullets.

I agree that if the manufactures thought they could make money they would produce the 54 but think their market analysis is driven primarily by whitetail hunters and it is surprising that some after market barrel maker hasn't given the 54 cal at least a limited production run.

Thanks Again to All