Been reading thru the history of the Plains Wars, men like Sitting Bull and Crazy Horse, super interesting stuff! Also sad and somewhat depressing as you realize these men witnessed the genocide of their people and tried everything in their power to stop it and ultimately failed.
But when wiki talks about specific battles that Sitting Bull and/or Crazy Horse's small armies involved themselves in, like Fetterman Fight or Box Wagon fight, it never really discusses the specific weapons the natives were using or how they obtained rifles and more importantly how they got ammo?
https://en.wikipedia.org/wiki/Crazy_Horse
and
https://en.wikipedia.org/wiki/Sitting_Bull
Were they really just storming well armed cavalry units with bows and arrows? or what?
While you are waiting for someone to answer your question, /u/partymoses answered a similar question in the past: How did Native Americans like the Souix Indians acquire so many modern repeating rifles?