Originally Posted by freakshow10mm
Velocity= trajectory. KE= penetration. When I look at ballistic charts and I see a velocity figure versus another I think faster bullet, flatter trajectory. When I see KE on chart, I think more KE, more penetration. I think the kinetic energy figure gives an estimate of the penetration of that particular projectile at that velocity. Velocity and energy are interdependant on each other. The higher the velocity the higher the energy. A KE figure gives me an idea of how deep it will penetrate into a body to reach the vitals. That is to say the same bullet with different KE figures, the one with more KE will penetrate deeper. KE is dependant of mass and velocity. Bullet design is also a factor and not taken into consideration for purposes of my ncoherent ramblings.
Kinetic Energy has almost nothing to do with penetration. Kinetic energy is the combined effect of velocity times mass (bullet weight). Bullet design and construction have far more affect on penetration than kinetic energy.
Velocity affects a bullet's performance at the target. If the bullet is lightly designed to open rapidly and expand to a wide diameter when making contact with the target; it will penetrate less than a bullet that is designed to expand slowly and slightly. It's simple, it is harder to push something with more frontal diameter and resistance through material than something that is narrower with less resistance. In fact, to an extent (there is a diminishing point), you can take two of the same bullets and shoot the target at different velocities, and the one with the lowest velocity will penetrate deeper than the one with the higher velocity. This is because the one with the lower velocity will cause the bullet to expand slower and to a narrower diameter than the one making contact at less velocity.
The opposite is true if the bullet being used doesn't expand at all; say a flat nosed FMJ bullet. In the case of this bullet, the higher the velocity the deeper the penetration.
So, forgive me if the writer quoted above was being "satirical" when he made his completely erroneous statement; but I could not resist the need to comment.
Oh, by the way. I think the perfect bullet would be a 10MM Auto 180 grain Barnes X-Bullet that would only expanded to it's full diameter (it is truncated to feed properly) when the target is hit and retain all of its weight as it travels through the entire target making a hole in and a big hole out and destroying everything in its path along the way. Right now Barnes almost has it right, but they need to increase the weight and decrease the expansion. When dealing with the slow velocities generated by handguns; it is massive tissue damage and hemorrhage that kills, not energy dump (KE) or any other such nonsense. Penetration is your friend; and the more penetration the better the friend.