Using standard factory ammo the edge would go to the 270 win and 7 mag. The 308 win is out. More pricey ammo like hornady light mag both the 270 and the 7mm have nice ballistics. They are both really close to trajectory if using like bullets and weights. Same with reloading both are close all depending on bullet selection and starting velocities. I have reloads in 270 win that match the 270wsm velocities and are very accurate. My vote would have to go to the 270win using medium weight bullets.