http://www.reloadbench.com/cartridges/300w.html
This site says it all. I had earlier read on another site that the bore design on these rifles made them less accurate, but I think whoever said that got mixed up, the only problem with this round is the fact that it's available in guns that have the free-bore feature, like the Mark V and other Weatherby rifles, and it is also available in rifles manufactured by other companies. Handloads in the manuals and the faster chronographed velocities were tested in the free bore set-ups, meaning that these cases generate such extreme pressure that they can actually blow out the chambers on certain rifles if reloading is not done very carefully.