A couple days ago, I had this fabricated where I work (out of .125" 5052 aluminum, two of them). I glued a textured piece of 3/16" rubber on the top and put small rubber feet on the bottom. Using a bi-pod under the barrel, you just rest the grip (AR grip here) on it and move the rest forward or rearward to adjust the elevation. By moving the rest like this and varying the bi-pod height, there is a range up to about 30 feet of elevation adjustment possible at 100 yards. The rifle sits solidly very nicely and with little recoil, this works very well - very fine adjustments are easy. It cost me nothing, so it was a great alternative to an expensive sled or rest system. Posted a couple pictures I took on my little "sight-in range" behind the house.