While I have not shot the Taylor & Co. M1886, I have plenty of experience with original and modified '86's in .45-70. Although I have not taken game with it, the Lyman 330 gr. HP cast bullet had a fairly good reputation on medium-sized game. OTOH, you can't drive a cast bullet faster than about 1600 ft/sec without experiencing leading in the rifling. With jacketed bullets, there are loads safe for using in late-model original or modern reproduction M1886's which can safely drive 300 gr. bullets up and around 1900 ft/sec. Check the Lyman Reloading Handbook #48 for smokeless loads. Obviously, if you use black powder, you won't get anything anywhere those velocities. Depending on what game you are hunting, you may want to go to heavier bullets for penetration. Certainly that would be the case, if you are going after griz or buffalo. I agree with setting 200 yds as maximum range. Frankly, I wouldn't shoot at game beyond 300 yds with a flat-shooting, high-velocity cartridge either. The average hunter, under hunting conditions, can hold about 6 minutes of angle. That means about 18 inches at 300 yds, which is about the size of the "boiler room" of an elk! Just MHO, of course. Best of luck with your new rifle. The '86 is a true gem!
Happy Holidays, Pard!