Over the years I have used various methods for my rear height adjustment when shooting from a bipod. Sand bags. beanbags, rear rests, even my fist. What I use now is a lab jack. These are small inexpensive scissors jacks that come in various sizes. They will hold more than enough weight to support a rifle. They come in various weight capability and plate sizes, 4"x4", 6"x6", etc. I find them to be stable, and provide a very fine height adjustment. I have added a thin rubber pad to mine. It serves no function really just like having one. I use mine to support the HS precision stock on my Savage 110 FCP in 338 Lapua Magnum, so it can handle the recoil. I have found with my stock, placing the jack under the pistol grip provides a good location for support and better recoil effect, since the bottom of the stock is tapered at the sling mount. This location does not interfere with my trigger hand placement. I align the adjustment knot to the left (I am right handed). after adjusting and during trigger pull process my left hand really has little to do. I have found grasping the fore stock will help return to target POI after recoil. The jack works great whether shooting prone or from a bench....not much use for standing or for kneeing firing positions though....lol