Survivor,
The voids in front of and behind the screw lug are intact. I didn't mess with them. I used modeling clay to form dams before and after the lug so that the bedding pad is about 1" long and 7/8"wide around the screw lug. Be sure to use clay to fill the gap around where the lug meets the barrel so you don't form a mechanical lock, and use release agent on the barrel and screw. The bedding fully contacts and supports the bottom surface of the lug a small even area (about 1/8" all the way around) of the barrel around the lug. This bedding and the rear pivot area of the forend at the reciever are the only places of contact. Before bedding, rough up the areas where the bedding will go with a dremel or other means, but be sure not to remove the existing spots where the lug rests. These act a points of reference to maintain the position of the forend when doing the bedding. They can be found by applying a little lipstick or prussion blue on the bottom of the lug and installing the forend. Don't remove the material where the marking shows up on the forend. When installing the forend after applying the bedding, just push it into position and then lightly snug the screw. Now leave it alone until it fully sets - be patient. Follow the bedding material instructions exactly and you will be fine. This has worked for me. I like the synthetic due to its low weight, good grip surface, toughness, and stability. It is simply impervious to water. Good luck.