HH,
The cocking piece varied from model to model and within models. Don't forget, this rifle was used from 1888 to the late 50s in essentially the same configuration.

I can't say I have favorite loads in this rifle, since I have several 45-70s and try to develop a load or 2 that's acceptable to all of them. Most recently I was working with Benchmark since I have a lot of it.
53 gr, 400 A-frame, Fed215 for 1946 f/s
61 gr, 300 Partition, " " for 2228
54 gr, 350 X, "" for 1924
53 gr, 405 CP/WFN, " " for 1950

Goof luck
SOS