Any difference in the wound channel between a 7mm Magnum 160 grain bullet and a 300 Magnum 180 is insignificant. Some folks make it a bigger deal than it actually is due to their own personal biases.
Felt recoil in most 7mm Remington Magnum rifles, with a few exceptions, is pretty much identical to that of a 30-06. A 300 Winchester Magnum recoils with about 35 percent more energy. In the recoil arena, the 7mm Remington Magnum is the smarter choice.