I would agree with JDJones on this one. Like the 308 family and to an even more closely compared example, the 284 family of rounds, you will not get much over what the parent case will get you.
The money required on custom dies, reamers and such would not be worth the extra 50 fps of velocity and that would be a gracious amount of velocity gain to expect in my opinion.
You would get just as much benefit from a properly designed, tight throated chamber in 300 WSM
. Keep the body specs tight to the case, keep the neck snug and the throat no more then 1/2 thou over bullet diameter. Throat angle should also be in the 1-30-00 range or less for top velocity potential.
Just my opinion.