Stormrider,
This is JMO based on certain facts.
The BOSS system from Bowning has a muzzle brake and weights that can be moved towards or away from the action in order to fine tune the sine waves produced by the barrel vibration that in exchange would either open up or close the group size. The idea was to have the bullets either consitently leave the barrel at the peak of the sine wave or at the bottom (valley) of the sine wave.
Now, if you have a custom rifle shooting 1/4" without muzzle brake and then using the same load put a muzzle brake on it and spect to shoot the same does not quite dove tail... it may be possible but not to be expected. It may shoot worst, it may shoot better but not likely the same. We can play a bit with the powder charge and bring it back to shooting how it was if it shoots worse with the muzzle brake. It may be easier to see no difference in a factory rifle than would be in a custom rifle, the whole idea is that the Boss system works, and very well, and we know why it works then the other is easy to figure out.
I do want to hear opinions from you all, I hope I expressed my self clear enough.
Thanks... Eaglet