I'm not familiar with Goat Tuff, but it appears to be cyanoacrylate, or "super glue". I think that would be OK, as it will seal the end grain, but epoxy soaked into the end grain and then built up enough to conform to the waxed action would be better. Sort of like bedding a rifle. No gaps whatsoever, seals and toughens the butt stock. A bit more work, but better long term results in my experience.

Men build too many walls and not enough bridges. -Isaac Newton