Why Hollow Points?

Since 10-04-06

http://seecamp.com/ammunition.htm

There are those sold on ball ammo, claiming that ball ammunition provides better penetration while hollow points are inconsistent on expansion. Although ball does offer excellent penetration, the streamlined configuration of ball provides the smallest temporary wound cavity. Air passes over the bullet with minimal resistance and turbulence.

Air is not trapped and compressed within a cup to be released on impact (hopefully with bullet expansion), as it is with hollow point ammunition, nor is it vigorously directed away from the bullet, as is the case with the outside concave surface of semi-wadcutters.

Both of these round types are shown in FBI ammo tests to produce a much greater temporary wound cavity in ballistic gelatin than ball. Logically, the shock value of temporary organ displacement translates into greater stopping power.

Sanow and Marshall, in their controversial study of actual shootings, have placed the 60 grain .32 Silvertip on equal par with 230 grain .45 FMJ ball for stopping power. On the face of it, the Marshall/Sanow results seem ridiculous. A .45 caliber hole produced by a 230 grain bullet would appear to be far more effective in stopping power than a puny 60 grain hollow point that may or may not expand to .45 caliber.

Missing from the caliber equation is the jet stream turbulence produced by the configuration of the bullet. A .45 bullet that is streamlined to pass through air with the least resistance may not provide the best stopping power.

The trapped and compressed air within the hollow point bullet along with compressed gelatinous mass produces a hydraulic effect when the bullet strikes soft tissue. If things go right, the bullet cup is mushroomed out and the bullet expands to a larger caliber. The degree of penetration is reduced to the degree the bullet expands. The more expansion one gets, the less penetration one gets.

Regardless of whether the hollow point bullet expands or not, there is still turbulence produced by the cup. This turbulence is absent from the streamlined air foil design of ball ammo.

The hollow point cup creates a jet stream that in flesh or gelatin produces a temporary wound cavity of substantially greater diameter than the bullet. This cavity helps allow for bullet expansion since the pressure of the compressed material in the cup is far greater than is the pressure found outside the cup.

For this reason, hollow point ammo generally expands better in bare ballistic gelatin than it does, if at all, in clothed gelatin. When the cup strikes a less resilient surface than soft tissue, the pressures inside and outside the cup are closer to parity and expansion is limited. This almost seems to me to be the ideal situation. If a perpetrator is lightly clothed, the ammo will expand for maximum stopping power. On the other hand, if the perpetrator is heavily clothed and we are looking for better penetration, the ammo will sacrifice expansion for penetration.