I've always used sand bags on the hood of my pickup, and I rifle shoot from a sand bag rest very often. I've used feed bags filled about 1/4 full of sand or pea gravel. Then roll up the feed bag and take a few tight wraps with duct tape, or you could just buy a sand bag, or bipod In my opinion. If you need a vice or sled or whatever. You need to practice on your marksmanship! "You" need to hold the rifle tight and solid! Not an accessory. Otherwise you will end up depending on the vice or sled all the time if you use it at the bench all the time and possibly develop bad habits. Zeroing a rifle should not be that difficult. A rest simply makes shooting from the prone position or from a bench more comfortable. Don't get me wrong. It definitely helps to stabilize the rifle, but it doesn't take much of a rest to do this. As long as it is not spongy or squishy like a coat or hooded sweatshirt. Also a sand bag naturally forms to any uneven surfaces. This is all just stirckly "my" opinion bud, and everyone has one. I'm sure vice's and sleds have there place somewhere, but not for simply sighting in a rifle. Hope this helps. Shoot fun, shoot safe and shoot strait!