Savage458,
I may be wrong about this but this is the way I understand the forces being created by one action of firing a gun. When the round first goes off the pressure created inside the gun is going to try and open the action around the hingepin. A crossbolt will help here to keep the action closed. This reaction only lasts for a few milliseconds. The the gun starts to recoil and to rotate somewhat around it's center of gravity which is in between the barrels. The recoiling of the gun is now trying to close the action tighter as the barrels move upward. The rotation of whichever barrel has been fired will try and rotate the gun in the direction away from the center of gravity of the gun. The backwards recoil is distributed to the stock of the gun and now starts it to rotating upwards around your shoulder pocket because the recoil is more than your shoulder can handle. All it does is to slow down the recoil and redirect it in the only direction left for it to go, upwards. The more drop to the stock from the center line of the bores, the more upward movement you get with any given load. I hope this helps you to understand these forces and how they apply to shooting your gun. Bob