I just measured and built a paper pattern test fitting and redrawing until I got it to look like I wanted.
The end cap is butt stitched so it there is no ridge to cut into your shoulder. Since this gun is used in competition, it is used mainly to keep the gun from shifting on the shoulder during rapid fire and reloading. there is no padding since target loads are used instead of hunting loads. Plus, in the heat of the moment, you don't really feel the recoil since you are focusing on the follow up shot/reloading.