Silencers, Sniper Rifles and the CIA

[Bob Prudhomme]

Interesting. I would also point out that the M-16, whose bullet wounding patterns are present in that paper, is actually the less lethal version of the AR-15, which was present in Dealy Plaza in the hands of SS Agent Hickey, quite near to the time the head shot was fired. I say "less lethal" because the Army, when ordered to adopt the AR-15 by JFK and McNamara, responded by changing the rifling of the barrel (which reduced the tumble of the bullet after contact) and by using an inferior powder, and adding an unnecessary manual bolt. The resulting kludge was named the M-16.

Hi Drew

Well, in a way, the change in gunpowder the Army adopted did make the M-16 less lethal, but not quite in the way you might think. The ball powder adopted by the Army had far worse fouling properties than early tests showed. As the M-16 is a piston operated rifle, and that piston is operated by propellant gases, and those gases reach the piston through a tiny "port" midway down the barrel of the M-16, fouling had the potential to close this port off, which it actually did; costing many American lives before the problem was rectified. However, when the ports were not fouled, the ball powder propelled the M-16 at the necessary +3100 fps velocity, and the bullets were just as lethal, if not more so, than anything fired from an AR-15.

http://www.thegunzone.com/556prop.html

While the M-16 went through several changes in the rate of twist of its barrel riflings, none of them had any effect on the lethality and instability of the M-16 bullet in-wound. The original Armalite rate of twist of 1:14 was found sufficient under normal atmospheric conditions but, when tested at extremes of -40° F. and +140° F., it was found insufficient to stabilize the bullet in-flight, and faster riflings were introduced. When the M193 bullet was replaced by the longer and heavier M855/SS109 bullet, it was again necessary to make even tighter and faster riflings, as longer and heavier bullets require faster rotational spin to stabilize them in-flight and prevent them from tumbling before they hit their target.

Getting to the target, and getting there stable and point first, is essential to the lethality of any bullet. A tumbling bullet might not even make it to its target and, should it hit side on, will not have near the penetration of a bullet hitting point first and stabilized.

When the M855/SS109 bullet was first introduced, it was believed its faster rotational spin would allow this bullet to penetrate much further in a wound than the M193 before it became unstable. This turned out to be untrue, as Fackler demonstrated and, in fact, it appears the M855/SS109 actually loses stability slightly earlier than the M193 bullet. One has to wonder if the reason might not be partially due to the steel "penetrator" that makes up the forward part of the core of this bullet. As there is a distinct difference in density between steel and lead, making the forward section of the bullet from steel would create an imbalance in mass between the front and rear of this bullet, and make the rear end of the bullet want to pass the front end in a wound.

This mass imbalance was the basis for the extreme lethality of the .303 British Mk. VII cartridge, adopted in the early 1900's and used by the British until the 1950's.



As seen above, the Mk. VII bullet core was lead toward the base, and aluminum in the nose section. This, combined with the spitzer point, made the Mk. VII tumble in wounds, making this bullet far more lethal than a spitzer bullet with a solid lead core.

More reading on the M-16 barrel riflings. Some of the comments following the article are quite interesting, too.

http://weaponsman.com/?p=7291