There is something terribly wrong with melee combat. I have an unmodded game. My Melee perk is currently at "one". Grognak's Ax does between 350 and 900 points of damage. If my character injests Yao-Guai Roast it does even more. Legendary Super Mutants die in one hit. This bug also effects other melee weapons such as Chinese Officer Swords, pipe wrenches, revolutionary war swords, et. al. Grognak's Ax just happens to do far more damage than any other weapon.

Another odd bit, this melee bug isn't always present.

Thank you for your support.