I bought a 1895 22" and have had it for about 2 weeks now without getting a chance to fire it yet. This kind of thread is encouraging though. I have some factory Rem 405gr, and Hornady Leverelution. Those will be the benchmark on what I compare my handloads to. I have some 460gr cast performance, and 405 gr remingtons to load up when the rest of the parts get here. I'm still trying to figure out where to start with the H4198. Hope I have as good of luck as you all did!
Marlin 1895 45-70 22" barrel
405 grain Remington JSP seated to 2.55" cartridge overall length and crimped with a Lee Factory Crimp Die
Winchester brass, 2.1" trim
CCI 200 primer
31 grains H4198 REDUCED
45 grains H4198 START 1800 fps
50 grains H4198 MAXIMUM 1950 fps
Marlin 1895 45-70 22" barrel
460 grain Cast Performance WFNGC seated to 2.525" COL and crimped with a Lee Factory Crimp Die
Winchester brass, 2.1" trim
CCI 200 primer
42 grains AA2230 START 1600 fps
47.5 grains AA2230 MAXIMUM 1730 fps
Sorry, I don't load the 460 CP with H4198. However, Coyote Hunter has a spreadsheet with numerous 45-70 loads which includes a 460 CP load with H4198.