No way. Where did you get the calculation from?
252 SpA Choice Specs Gengar Hidden Power Ice vs. 252 HP / 4 SpD Assault Vest Goodra: 92-110 (23.9 - 28.6%) -- 97.3% chance to 4HKO
The base power of HP is only 60. A STAB shadow ball does the same damage as a SE hidden power on Goodra (Goodra is...