I think Dean's got it. Here's a definition lifted from Morris Hallowell's web site:
Pitch - The angle of the butt of a gun in relation to the line of sight. In America, pitch is measured by resting the gun with its butt flat on a floor, the top of the receiver against a wall and its muzzle pointing up. The distance of the muzzle from the wall is the gun's pitch down. In England, pitch is determined by measuring the length of pull, separately, to each of the heel, the middle of butt and the toe.
I have no idea what the English method means. I'll stick with the colonists' definition. Incidently. this means that a long-barreled gun will have more pitch than a short-barreled gun, with identical stocks
