.40-70 SS bullet choices

Have just received a C. Sharps 1877 JO Lower Sporting Rifle, chamber is .40-70 SS
(based on the Hornady .405 brass trimmed to 2.5").
Picked up a couple of boxes of 350 gr cast bullets when at C. Sharps, and figure to use AA 5744 powder (at least at first, then on to BP later).
I'm thinking along the lines of an LBT flat nose bullet to have a mould for, later on.
Any of you folks using .40 cal cast bullets out there for hunting?
I'm leaning towards a 300-340 gr weight, but open to input from users.
What bullet weight and shape are you using?
regards to all,
outsidebear