Tossing Around Some Caliber Choices

[Caprock]

I just bought a Roller # 1 sporter with single set trigger. Fine and dandy but its 32 RF. That won't last long as my first inclination is to slap a 50-70 barrel on it. As this rifle is destined for hunting the choice is appropriate.

Musing along, did I read anywhere about chamber dimensions and PPB for this round? Just can't pin it down.

Too, the thought of maybe a 50 with the 2 inch long cased popped up but I can't remember the historical basis for that one at all.

Finally, another that crossed my mine is the 44-100 straight but maybe throttled back. If a 45-70 is sized down to 44 does that roughly approximate the 44 Ballard or Maynard?