Actually I set my shoulder to the back of that wood and the butt of the rifle fits always into the same spot without a canter to it. It helps control the recoil as there is a small leather strap in there also, so the gun can never kick out of control (when I remember to use it). With the wedge you slide under the butt of the rifle it will adjust the level of the rifle so you are not trying to hold it all up on your own. Also it makes a nice place to rest the rifle while I check the target. I swab it out, leave the breech open and then walk down range and the rifle is up out of the way of my over grown labrador that thinks all rifles are beautiful and should be bumped into.