Originally Posted by tipoc
...the mass of the bullet and it's velocity and energy are factors...
These aren't three factors. They're just two. With the mass and velocity you also know (can calculate) kinetic energy. Mass and velocity also tell you momentum.
"It is long been a principle of ours that one is no more armed because he has possession of a firearm than he is a musician because he owns a piano. There is no point in having a gun if you are not capable of using it skillfully." -- Jeff Cooper