Metal points from the Indian Wars (1820's to 1890's) actually aren't very common because much of the fighting was done with guns. The Native Americans were still obviously using the bow and arrow as well, but for the most part the trade for the classic metal point never really took off like the trade for beads and other things. The big fur trading companies of the day tried to get them on metal points thinking it would be a popular item, but tribes preferred knives, beads, kettles, textiles or liquor. Later it was powder and lead.
I've never found one, but I saw lots of them when I lived in Montana. Becareful about buying them, to me they seem to be about the easiest artifact to fake since iron rusts so easily. I see pieces on eBay all the time, but rarely see any that I think are authentic.