I have a rifle that has a picatinny rail on the underside of my rifle butt (see photo). I use a leather rear bag and find that the rail is getting caught when it recoils, causing the rifle to lurch slightly to the backwards and to the right instead of going straight back. Is there an attachment anyone knows of that I can use to provide a flat surface to reduce the friction with the rear bag? Worst case I'll put some duct tape over it and see how that works.

