I've read of measured case capacities being about 45gr vs 52gr. That's about a 15% bump, which should indicate around a 4% velocity bump if pressure is held constant. Using a 3200fps MV, that should point to something like a 130fps gain for the Creedmoor, or at least something in that ballpark. I've also read reports from shooters that saw 100-150fps difference when owning both chamberings.
^^^^^ THIS ^^^^^
If you're actually getting significantly higher velocities than those easily calculated via Mule Deer's 4-1 ratio rule of thumb, you can be sure that you're also getting that performance bump through significantly higher operating pressures.
