Nice post about energy but it completely neglects momentum which is more important in handgun bullets than energy, IMO, especially when it comes to penetration. Mass is more important than velocity when it comes to momentum.
momentum = mass * velocity
Jim's Rules of Carry: 1. Any gun is better than no gun. 2. A gun that is reliable is better than a gun that is not. 3. A hole in the right place is better than a hole in the wrong place. 4. A bigger hole is a better hole.
no guns = might makes right