....... the most significant thing you are accomplishing is to achieve maximum contact between the butt and your shoulder pocket, IMO.
Generally, I would agree with what Jim Legg posted. However, from repeated experience, both personal and with students, I sometimes find determining additional factor(s). Specifically, sensitive places on shoulder resulting from injury, deterioration, operation, etc. Sometimes it is toe of stock that digs into sensitive area(s), sometimes it is buttplate hitting sensitive area(s) harder (and angle of butt/pitch might need to be different), sometimes it is roundness of buttplate, sometimes curvature of buttplate. All this can get very personal to individual and result in one gun being much more/less comfortable to shoot than another, which, in turn, can affect one's hit%.
Because I and most folks I help shoot are using old doubles with hard buttplates, lace-on recoil pads with adjustments to thickness and shape of inserts, as well as PAST recoil sheilds or similar protective devices are essential means of compensation. Still, sometimes shooter has to find that "right" gun for him/her. Seldom is cutting stocks on these old guns an acceptable option.
Niklas
