It is based on the 8mm Rem case. It should have ballistics very near or just a hair faster than the 270 Weatherby Mag. There is almost no difference between the 7mm STW and the 7MM Weatherby Mag. The difference should be simular in the 270 versions. That would be a close ball park comparision. It would also be close to the 270 WSM but a little faster. Maybe.