Does anyone know why there is a "drying" or "shrinkage" period after an animal is taken before the official score is done?

I'm not being critical, I'm just curious.

A friend of mine just killed an 84inch Pronghorn and he mentioned that he had to wait until it dried before it could be scored officially. Neither of us knew where this rule came from though....any thoughts or reasons?

Boone and Crockett do this just to keep things even. The skull plates have tissue between the them that when dry shrinks quite a bit. You can manipulate the spread with the skull wet. When dry the skull is more consistent. It is not really fair to compare a fresh kill with one that was killed a hundred year ago. I don't think that you loose much from antler or bone shrinkage but mostly from the joints in the skull plate.

I have saw people place a board between the antlers to maintain as much spread as possible during the drying time period but have never tried this myself. You could easily gain up to 4/8" this way though on a big antlered animal.

Hope this helps, and congratulations to your friend.
God Bless, Louis

Good answer Youngoutdoors, that is pretty damn right, but I will tell you that antlers will definitely loose some length too, I have a friend that has several B&C whitetails, and was the first man in Georgia to kill both a B&C and a P&Y whitetail here in the state. He had a couple of trophy's lose nearly an inch in overall LENGTH during the 90 day period, from the same scorer.
An 84 inch Pronghorn should have NO issues still being B&C!!