Yes, if you want something with scientific accuracy, you would need to conduct a scientific experiment.
Ed Sisk and others have done that.
http://accurateshooter.wordpress.com/2009/02/05/barrel-length-and-velocity-barrel-cut-down-tests/But I was asking for the real world benefits perceived by those who hunt with single shot rifles, such as in shooting heavier bullets in the 6mm Remington, .257 Roberts, .270, .30-06, 7mm Rem Mag, .300 WM, etc.
