I would like to see the data. I think this may be a rare case where a factory load is not as hot as it should be. If you compare Winchester's ballistics for the 300WSM vs the 300 Win Mag, the 300WSM comes out ahead, but if you look at any other load data, the 300 Win Mag comes out ahead. I think it is a case of creative marketing on Winchester's part. They download the 300 Win Mag to make their new baby look better. Under normal circumstances using the same bullet weights, the 300 Win Mag tops the 30-06 by a goodly margin. I love both cartridges though and both will always have a place in my gun closet no matter what new whiz-bang superhyped magnum comes along.