A double that is regulated for anything other than the full power load is nearly worthless.

However, the good news is that if you regulate for 570 grains at 2150 fps, it is very easy to get a lighter bullet to regulate at a lower velocity. For example, I use 110.0 grains IMR4831 behind a 570 grain bullet in my .500 NE, but I can also shoot a 500 grain cast lead bullet ahead of 45.0 grains XMP5744 powder and it regulates perfectly and has the same POI at 50 yards as the full power load.