“Your rod was your last round.”
Can’t remember the name of the book but it was about a mountain man who was chasing down a band of indians that had raided his camp and killed his young wife. He chased them for months taking them one at a time until it came to the leader of the group. He was out of bullets and the leader was coming after him with a tomahawk and a knife. He threw some powder down the barrel, primed the pan and stuck the rod in the barrel and shot the leader at about 5 ft. This was over 50 years ago and I can invision it as if it were a movie.
Sounds like John Garrison aka Jerimiah Johnson. There were a couple of books about him. The movie was loosely based on one.
Legend has it that Garrison aka Johnson aka Crow Killer aka Liver Eater was captured by the Blackfeet and was to be sold to his mortal enemies, the Crow. He supposedly chewed through his rawhide lashings, killed the Blackfoot guarding him with his bare hands, cut off the guard’s leg to use for meat on his 200 mile escape and made it.
I know this is a, ummm, delayed response but I think you are referring to the Crow Killer, “Liver Eating” John Johnston.
After all his adventures funny thing was he died in an old soldiers home in San Francisco.