"What I shot those white tailed deer with was factory Winchester ammo advertised to be at a MV of 1850 fps."

That is the factory .45/70 ammo I was talking about. Fed and Remington, I think - obviously Winch. as well.

2,200fps is what my Bro's .45 3 1/4" Shiloh Sharps got with 62.0gr. Re#7.

Current Hodgdon 45/70 300gr. data - Annual Manual:

Hodgdon's data for Trapdoor Springfields runs up to 28,000CUP.
Hodgdon's data for 300gr. Sierra HP runs up to 2,221fps with H4198, 2,138fps with IMR 4198, 2,142fps with H322,
2,113fps with Benchmark, 2,135fps with H335, 2,020fps with Varget. IMR 4064, IMR4895 and IMR4166 are all between 1,957fps and 1,992fps.
Their data for Lever guns runs to 40,000PSI'
their data for Modern Rifles run up to 50,000CUP.