Among the handful of folks who come here each year employing a guide, I have never seen or heard of a hunter showing up armed with a 45-70, this in spite of the fact that some do come armed with bows.
There seem to be two general classes of bear hunters; one which feels the cost of a bear hunt and wants to go home with a very nice or at least good representation of a brown bear. The other group includes those who have a certain goal in mind, the odds of scoring and the costs be damned. These latter hunters are, of course, fewer in number, but not rare. They are the ones who want only a 9 1/2 footer or bigger, want to arrow a bear or use some other handicapping method. The 45-70 may not be viewed as enough of a handicap by those who want he prestige of taking a bear with one and it may seem like too much of a handicap for those who just want to favor their odds of bringing home a bear - but that just me speculating.
As for guide use, I know some fellows carry a Guide Gun (450) as a backup to their regular backup rifle. A usual backup rifle is frequently chosen for its ability to make longer shots when necessary and the 45-70 does not fit the bill. OTOH, a 45-70 or 450 carried as a secondary backup can be a useful when shots might be measured in feet and one is crawling through the tangles.
