Brownells Acra glass or any good epoxy resin mixed with flock (ground fiberglass fibers) for structural areas that need strength. Mix it to the consistencey of cake frosting so it stays in place. Wet the area you are putting it with resin first to enhance bonding.
Anyplace you need filler but not strength, like under the barrel use microballoons instead of flock as its much lighter weight.
Last edited by tcp; 12/23/19.
