Cast bullets is far more about fit than alloy. 10-12 bhn makes a great game bullet in the Whelen cast 1-2 thousands over groove. Cast at lineotype hardness also can shoot very well but is brittle which can shatter on bone. Use the same thinking on your Whelen that works well in your 45-70 and your good to go. Mine is a 1-14 old custom Springfield. I shoot the Lyman 35806 280 grain RN with gas check at about 1950 fps. I use imr 4759 but lots of powders work at that range of speeds in the Whelen. Aa 2015, TAC, h335, 4895 sort of range.
