The stock weld must be muscularly relaxed, meaning the full weight of the head resting, not lifted from, or pressed down on the comb. It must be this way to assure consistent perspective of aim, as well as consistent control over the rifle from trigger pull to bullet exit. Pulse is about tension, not having a muscularly relaxed head. Usually, an adjustment of both butt-to-shoulder and stock weld will be required to get the neck relaxed enough to where pluse is no longer felt. 