In this case Greg Ellifritz over at Active Response Training got to it before I did: how bullets sometimes ricochet when head shots are taken.
Those of us who have some experience hunting may have encountered this phenomenon: a frontal head shot on a sloping skull will sometimes slide off, doing nothing more than hide damage as the animal stands there thinking “wha’ happened?”
We think of bullets as being predictable and invincible, but it’s possible for even seemingly soft objects to affect their trajectory. This is not unusual when dealing with fast-moving objects; consider, for instance, a spacecraft re-entering the atmosphere. Air is relatively ‘soft’, but even an approaching shuttle or capsule must impact the upper regions of the atmosphere at just the right angle or risk a bounce back into space.
Much the same thing happens with bullets and water; shoot a bullet at right angles to the surface and the bullet goes in, but at a steep angle they skip with much of their velocity and energy intact. (I learned this at an early age with my .22 rifle at our pond: I discovered that I could aim at the water and with great care bounce the bullet into a target stapled to a tree on the steep bank. Do not try this at home – I was younger, and dumber, back then!)
It’s all about angles. When we combine the curved surface bullet with a curved target (and particularly a complex curve like that of the human head), it’s entirely possible for that small point at which the two contact to have an angle of incidence such that the bullet is deflected rather than penetrating. It happens fairly frequently, actually, as the articles which Ellifritz has linked show. When you factor in the movement of the head making a constantly varying angle, it becomes easier to understand why bullets bounce off them occasionally.
This is why I’m not a big fan of the ‘failure to stop’ drill taught at so many schools. Aside from the logical weaknesses of the technique (which I’ll go into in a future article), the physics of hitting that moving target in the small area where ricochet is least likely to occur make it a risky proposition at best.
For a police or military marksman, who can set up and wait for the right angle, it’s not nearly as much an issue. For the cop on the ground or the private citizen facing an enraged and moving assailant it’s another matter entirely. There are other places you can aim which will have an effect on your attacker’s ability to present a lethal threat without the risk of ricochet, and you should know what they are (which is also another article, but Ellifritz talks a bit about them at the link.)
Bullets are not magic, they’re not perfect, and they don’t always behave how you expect them to. Be sure your targeting is appropriate!
-=[ Grant ]=-
- Posted by Grant Cunningham
- On January 22, 2014