Your Bullets are like My Bullets
They apear to be .44-70 or .45-70. My brain is fuddled right now. These are what Custer would have shot at the Souix. I have two types, a shorter one with a large hole in the base (carbine?) and a longer one with a smaller, almost pin sized hole in the base. It appears you may have both also. Do the holes correspond with sizes in yours?? Mine came from a guy who dug on private land near Ft. Laramie and apparently found the 1870's shooting range. They aren't near as torn up as yours. Must have been in a sand pit or something. Perhaps this also explains the quantity in a limited area. Perhaps Mr. George could give the exact info on these, but I think I am close enough to get you going in the right direction.