I've shot a fair number of deer with standard loads in the 45 LC and the 44 Special (11 and 8, respectively if my logs are right, but I didn't always get things entered). While you are "in the money" in terms of velocity and energy out to around 50 yards, my experience makes me a little suspicious of saying that your getup will perform similarly to the 45 or the 44. I've used round nose, semi-wadcutters, hollow points, and hard cast and soft cast. In general terms round nose killed the deer, but it took them quite a while to figure out they were dead. Hollow point tended to fold closed rather than opening up if the lead moved at all. Soft-cast round nose didn't change shape at all unless they hit a bone. Best performance in terms of quick kills and penetration was with hard-cast semi-wadcutters having large flat noses (meplats).
At your velocities I wouldn't have much confidence in an RB penetrating deeply, or expanding even with pure lead. The conicals available will certainly penetrate deeper due to higher ballistic coefficients, but with their small meplats I wouldn't expect them to kill as quickly as something with a bigger flat nose. I also wouldn't count on much or any expansion with the conicals.
If you could find a conical with a big flat nose, I would expect it to be pretty reliable to around 50 yards. Even with that, I would lace on your tracking shoes. With a standard conical or RB, I'd bring a Serrengetti bushman to help you with the tracking chore on shots that didn't land right or in thick brush.