I think all the above postings pretty much covers it.
I have an 1886 takedown Miroku, and here are a few of my experiences.
Trap door loads work fine, and don't beat you up. 300 to 405 grain plain based bullets up to 1400 fps work good without leading using IMR4198 or Unique powder. 0.458 to 0.459'' bullet diameters are good, but 0.460'' maybe a little too tight for my chamber. I use gas checked bullets only because I have been using higher velocity loads, which I am now turning away from. RCBS plain base mold 45-325, would be good, or something similar. If you want off the shelf bullets take a look here, https://www.bearcreeksupplybullets.com/price-sheet, these work good.
Full power 1895 loads are ok in the newer 1886 rifles, but 5 or 6 of those is more than enough on any outing especially if it has a crescent butt plate.
As for reloading the 45-70, it is probably the easiest cartridge to load.