Probably most are either offhand at relatively short range (50-100 yds.) because we did/do a lot of deer drives or from the 'offhand sit' where I am sitting on a stump, log or something and raise the gun to my shoulder and shoot.
There's been some longer (200-350 yds) that were from the more classic kneeling or sitting positions. Lately, I seem to be finding a tree or something solid to lean against. Can't say that I've ever gone prone to shoot a deer.
Putting a loaded gun on a vehicle in Pa. is illegal while hunting and I don't hunt from deer shacks so no window sills.
Dale
