Frizzellr-In order to compare recoil you must test the cartridges in identical guns.Weight,stock design and recoil pad will all effect recoil.A lighter 7mm can recoil more than a heavy 300 and an ultralight 270 can recoil more than both of them.The 7mm mag uses less powder and drives an equivalent weight bullet with less velocity than the 300 mag therefore with all other factors the same the 300 will recoil more.This is simple physics.Most people also use lighter bullets in the 7mm than the 300 but still maintain section density and penetration.As an example a 160gr .284" partition has a higher sectional density than a 180gr .308" bullet so the 160(284) will penetrate as least as well as the 180(308)By using the lighter bullet in the 7mm recoil will be reduced even further.I have fired both calibers myself in identical remington 700's and the 7mm mag recoiled noticably less.