Thanks for the clarification, Mike. Actually, when I wrote to chamber to .50 Alaskan, I was thinking of the new or re-bored if possible .50 cal. barrel and instead of going .50/70 simply chamber it to .50 Alaskan as a better choice. It's easy to blow out the .348's straight and they are very strong brass. Tool, there is loading data available for a starting point.

My brother is currently testing a new cast bullet at 600gr. in his .50 Alaskan M74 Sharps and has it shooting 'just over' 1 inch 5 shot groups at 100 meters- using black powder. Smokeless loads are easy for this sort of accuracy in this ctg.