3 loads come to mind for the 2 3/4" hull as per Greener, all with round ball.
110gr. at4 drams; 165gr. at 6 drams; 191gr. at 7 drams.
I would not personally shoot the 6 or 7 dram loads in that light a rifle. I think the 4 dram load would be quite sufficient and even a 3 dram 82gr. charge might be quite enough - for me - with a Magnum PAST shoulder protector under my jacket. Already have torn cartilage there and don't need more.
-------------------- Daryl
"a gun without hammers is like a Spaniel without ears" King George V