I'll do my best as it relates to what I do. I guess the best assumption is that it greatly depends on the school, style, and smith. Some guns have butt mouldings, some do not. This feature will generally raise the cheek piece, and the cheek moulding. The amount that the cheek piece projects off the stock, depends on a few things. The width of the butt plate, how thick your stock blank is, cast off also is a factor. The taper of the cheek piece towards the front is generally to the width dimension of the wrist and points to the center line through the wrist. There's more but it gets very complicated to explain it in words. I feel Bill Buchele's Book "Recreating the American Longrifle" really does an excellent job of explaining it in words and drawings. Check it out, you won't be sorry. ...Geo.