The thing that's never mentioned about the .30's mathematical advantage is that in order to capitalize on it, the shooter needs to execute the exact same shot with a .30 as they did with a 6. With the increased recoil, torque and overall gun movement of even the mildest .30 compared to a PPC/BR....that's a very, very difficult thing to achieve shot after shot and throughout an entire yardage. A shooters table manners with these .30's has be virtually perfect. They are very unforgiving. The 'good' you get comes at a cost.
The bullet diameter 'advantage' is quite a bit less on a .30 that most realize. The radius is what's really relevant. For all intents and purposes, the ballistics of a .30 and a 6 used in real Benchrest competition are virtually identical.
I've often said that for an average shooter, they would do better over the long haul shooting a good 6 over a .30. Grand Aggs are won at 200 and that's where the 6's can be an advantage. The tuneup and tune window on a good .30 is where they've got the 6's by the throat.
