They are skim bedded the same way you would skim bed a rifle in a stock. I use JB weld. Apply a very thin fine release agent to your action. I use kiwi neutral shoe Polish. Then hit the bottom mounting surface of the base with some 800 grit to give it a little grip. Also coat your mounting screws with release agent. Put a small amount of bedding compound on the mounting surface of your scope rail and mount your rail. Do not tighten the screws enoungh to squeeze all the bedding compound out. Just enough to snug it up and get a good bedding surface. Just like bedding an action. Clean up excess with qtips and allow to setup over night. This is just a quick run down if you do a search on Google I'm sure you can find better instructions and photos. Hope this helps.