By Andrew Betts
No, it is not the title of a sci-fi themed adult movie, it’s the line of CNC machined solid copper bullets from Lehigh Defense. Their Extreme Penetrator line is reminiscent of a Philips head screwdriver and the projectile is available in a variety of calibers, both as loaded ammunition and as components. The company claims that it not only penetrates relatively deeply as the name indicates, but that the “progressive nose geometry” can create “a permanent wound cavity diameter exceeding that of most expanding bullets.” They go on to claim that this “magic” is due to some ambiguous fluid dynamics which they liken to “sticking your thumb over a garden hose.” They even go so far as to claim a permanent wound cavity that is 2-4 times greater than traditional solid projectiles and some unspecified amount greater than expanding ammo. These are some extraordinary claims. Does the product live up to the hype?
To rationally examine the claims that Lehigh is making, we should first consider whether the claims are consistent with what we know about the mechanics of projectile wounding. The best resource on that topic is a paper published by the FBI called “Handgun Wounding Factors and Effectiveness” which summarizes what the agency has learned through testing, examination of cadavers, and statistical analysis of shooting incidents. One of the fundamental points made in the paper is that, at the speed that handgun bullets travel, the temporary stretch cavity is not a significant wounding factor. This is in contrast to much higher velocity rifle bullets, which can produce damage through tearing caused by the sudden and violent stretching of tissue. In other words, rifle bullets impact at such a high speed that the temporary stretch cavity stretches past the elastic limit of the tissue, increasing the size of the permanent cavity beyond tissue that was in direct contact with the projectile. Pistol bullets are moving too slowly to cause this effect so tissue simply stretches and snaps back to normal with no substantive damage aside from some bruising. The paper concludes that only tissue that comes in direct contact with the projectile can be damaged by a pistol bullet. That means that the claims that Lehigh is making are in direct contradiction to what is known about wounds caused by projectiles. To be fair, though, perhaps Lehigh discovered some new mechanism that was previously unknown. To rule out that possibility, we have to consider the results of independent testing.
There are two primary takeaways from this test. The first is that the bullet really is capable of some ridiculously deep penetration, especially for a projectile with such low sectional density. The deep penetration is most likely a result of the moderately high velocity combined with small frontal area and a hard material that simply does not deform. The second takeaway is that there is quite obviously no more tissue damage than is produced by a simple FMJ. The ball round actually produced more damage when it yawed and traveled sideways through the gelatin for a short distance starting around the 6” mark.
9mm ball does not exactly have a reputation for impressive tissue damage, yet it did destroy more “tissue” than the Extreme Penetrator in this test. There simply appears to be no support for Lehigh’s extraordinary claim. It should come as no surprise that the ammo fails to perform as advertised, though. Lehigh is essentially claiming that you can have your cake and eat it. Projectile wounding, like every physical action, is a dance of compromises. If all other factors (weight, velocity, projectile diameter, etc.) remain the same, varying the projectile’s design can only increase penetration if that design change also results in decreased tissue damage. Conversely, a wide swath of crushed tissue can only be produced at the expense of reduced penetration. In other words, the volume of tissue that can be damaged is relatively fixed. As the penetration goes up, the width of the wound track must necessarily decrease and vice versa. You can’t cheat Newton. As cool as Lehigh’s bullet looks, it does not defy the laws of physics.