Getting back to the physics (earlier in this thread), consideration should also be given to the additional force of the reaction of the projectile and powder being accelerated down the barrel (evident as recoil). I did some calcultaions for a 308Win and the acceleration force can add another 20% on top of the force from the pressure alone.

So even if the case head is the same diameter and the pressure is the same between two cartridges in the same action type and size, the cartridge with the heavier recoil will exert more force on the action.