Originally Posted by
charlie b
Force applied to the bolt face, and then the lugs, is related to recoil, but, not exactly. The force on the bolt is due only to the chamber pressure applied over the area of the bolt face. So, for the same chamber pressure a larger dia base means more force on the bolt.
There is also the rate at which the force is applied, but, that gets a bit complicated for these discussions. As long as you are in the elastic range of the material it only affects fatigue failure.
Recoil is determined by the acceleration of the mass of powder and bullet down the barrel. Again, related to chamber pressure, but, not a simple relationship.
You can have a max chamber pressure with a small bullet traveling fast and a lower chamber pressure with a heavier bullet traveling not so fast. The heavier bullet can have a higher recoil than the smaller, faster bullet, even at a lower chamber pressure.
Note: last portion of this was wrong so I deleted it.