Probably a little bit overdone but below you will see my new indoor range backstop. I have 18 yards available in my basement. Features 1/4" 4' x 4' steel plate, lag bolted into 2" x 8" frame, mounted on to left over 8" x 8" posts, with 2 layers of 3/4" plywood sandwiched for the floor, covered by 8" of sand. Pellets hit angled plate and drive into sand. Works very well with all of my pcp air rifles.