sfno72 and mcameron
First for the OP, you might try some IMR4227 at starting published loads.
For the rifle, Lilgun, H110, and 2400 are all on the slower side but will give you some real power for that Rossi.
Guns have only two enemies, rust and politicians!
Deer are amazing creatures....so please don't burn the sauteed onions and I'll pass on the steak sauce, thank you.