But you want to use a crossbow and hunt during bow season? The Crossbows of today are kinda high tech don't you think? You'll still have to judge distance same as a bow and in all honesty a bow is more accuarate.
Why didn't you get a range finder or just mark distances around you treestand?
I have a great respect for the true primitive weapons hunters
Flintlocks and recurves and longbows?