Rocky Mountain Hawken

What is the rate of twist? The .50 caliber is 1-48 I believe and the .54 is 1-66. So I really do not see them shooting minnie ball. Although the .54 might have a chance. Personally I would shoot the roundball and be happy with that. I cast minnie in .50 and .54 and have yet to find a rifle that shoot them (in my collection) satisfactory to hunting accuracy that I demand.

Welcome to the forum. Its a pleasure to have you here. As for your rifle... because of the twist, they just do not shoot conical bullets well, in my experience with them. I have several roundball rifles and they have similar twists. I purchased them because they were roundball rifles.

Never under estimate the killing power of a .54 caliber roundball. They will drop large game animals a lot better then you might think. Also with the slower twist you have, you can push the ball a little harder and it will not skip the rifling. So even with a heavy powder charge for the larger game animals, it will be accurate and be an excellent hunting weapon.

If you have any of them REAL conical bullets left, and want to try them again, don't push them hard. 60 grains of powder is plenty and they will sometimes behave better.

I would load a .530 ball with a .018 patch and a good lube.