pluckit
One of 6the reasons they used some what smaller calibers is because they had to carry enough ammunition to last a long time and one of the reasons it was effective was because of the 44 and 48 inch barrels giving a considerable difference in velocity. If you look at history you will notice that as time went on the trend centered around the more ballistically effective calibers which had more terminal effect. If you are going to take down a grizzly or buffalo with a 45 you better have a very fast horse and stay on him.