I'm not sure what the original box surface is for the Big Bully but this ball is plenty strong for heavy oil in out of box grit. The only ball I've ever thrown stronger in heavy than this one is the Super Carbide Bomb. If I had to guess I'd say out of box the BB is 800 or so grit so I guess that you could take it down a little bit but this surface is already very strong, maybe your drilling doesn't match up for you?