A 45-70 shoots like a rainbow, the further away a target is the higher you need to aim. For any of the animals that you listed except for the brown bear I would have to say that 150 yards would be max. For the bear I would keep it under 100 yards just for the simple fact that you don't want to make him mad.
A lot of brown and black bears have fallen to that round and I would figure that most of them have been under 100 yards.
I totally agree with you critter on the 150 yds with the 45-70. Like you mentioned they have a trajectory like a rainbow. Definetly would'nt be my 1st choice for an open area where shots could surpass 200 yds
Hunting can be slow and frustrating if Mother Nature throws a warm hunting season at you. But things can take a drastic turn for the better with the onset of a cold snap. Whether you get snow or just a good, prolonged cold front, the hunting can improve on a dime. But cold whether can also make certain parts of the hunt more tedious. Here are some things to keep in mind when your prayers for cold weather finally pay off.
You can see a your quarry's breath when it is cold outside...