The OP's question was a .45/70 on a broadside rib shot at 200 yards... I would take that shot with just about any .45/70 load or bullet... AS LONG AS... I knew that I could put it through the lungs... with cast loads, I would have to be sure of the range and confident in my practice at that range. Most full loadings and non-frangible bullets from centerfires of .243 and up, would cleanly expire a 200 yard moose on a broadside lung shot... of course some are better than others... which is why we have shooting forums... someplace to disagree and vent. I reserve my .45/70 reduced cast loads for deer under 100 yards... but would not hesitate using a full power jacketed or hot cast load on moose... but then my .35 Whelen mannlicher would pout.