If your not reloading, I would say Garrett or buffalo Boar for hot factory loads, the others are limited due to trapdoor pressures in the old type 45/70's. BuffaloBoar&Garrett is very costly Ammo, around $50.00 and up for a box of 20, if hot loads are what your looking for they have them, A little over kill for most of our game here unless your hunting Moose, also good if your hunting brown/griz/cape buffalo etc...very large animals over 500 Pd's, now if your reloading the sky is the limit, read about Elmer Keith's loads, He got a few hot ones that he developed in his time, I like H4198 powder using 350-405 jacketed bullets there is some really hot loads using H4198, this is a Hodgdon powder. Stay within the spec's and you can find many hot loads for the 45/70. Aim small hit small. RAMbo.