Post deleted by ScottS

Well, its the same principle as getting hit by a guy. If his fist is against your arm when he pushes forward to hit you the energy is distributed to a larger area where if he was able to rear back and smack you in the arm the energy will be more focused to where hit fist meets your arm. I hope that this helps.

Drum

Any loss of energy of that gun as it kicks back would be due to friction encountered as a result of the earth's atmosphere (air). Not much loss of energy occurs because the distance to the shoulder is so short. Therefore most of the energy is felt as it hits the shoulder.

When you do the conservation of momentum calculations, if the rifle is off the shoulder, you obtain a high velocity for the rifle and hence, a high recoil energy. If the rifle is held firmly against the shoulder part of your mass is involved, so the whole system comes up with a lower velocity and energy.

As far as the decelleration, that mostly occurs in the inelastic collision of buttplate and shoulder, not in the air. That rifle is still moving when it hits you.

Well, dont I feel like the idiot here, LOL.

Drummond