Hears is my tip.
The 1800 hunters needed a range finder more then today’s hunters do.
Hear is how to build one.
Take a ¼’ Dow rod about 8-10’ long and a peace of board about 3feet long (that is about how tall an average deer stands in this area). Stand the board up ageist something. Walk away from the board 50 steps then hold the Dow rod out at arms length. Line the top of the Dow rod up with the top of the board. Then make a mark on the Dow rod at the bottom of the board. Then step of another 50 and repeat the process. Repeat the whole process until you have walked 3 or 400 yards. The when you are ort hutting the Dow rod at arms length, place the top to the deer’s back and count up from the bottom mark to the mark at the bottom of the deer’s feet multiply by 50 and that will be the yardage to the deer. I toke my muzzleloader along and marked the holdover on the other end. For that I put the top of the Dow at the point of aim and marked the bullet struck.