358owner, you probably already know this, but when loading a .45/70, be VERY careful to note the OAL of the loaded rounds. Lots of older rifles allowed many of the heavier bullets to be loaded out to longer seating lengths, thus effectively increasing usable internal capacity. The lever guns require a shorter OAL, and thus, limit potential powder chamber capacity, and this can increase pressures DRASTICALLY if loads for the longer seated rounds are used.
Your loads sound quite safe to me, offhand. I'm using 300 JHP's over 57 gr. of H322 in WW cases with WLR primers, crimped in the groove.
I know what you mean about some of the stout .45/70's really "getting your attention." I tried some hellbenders in a Browning B-78 once, and that crescent steel butt on that one will REALLY hurt a fella', if you give it a chance! I did. ONCE!
Shooting a big ol' bullet kinda' makes a fella' squint at some of the ads in the magazines, doesn't it?

These itty bitty 300's really whack whitetails down south.