What’s All the Ruckus about the Extreme Penetrator?

This is a guest post by Andrew Bettsextreme penetrator

There has been a great deal of commotion over the Lehigh Defense series of Extreme Penetrator bullets in recent months. It is without doubt an intriguing design with a provocative name. The bullet might remind a person of a Philips head screw driver and it is CNC machined from solid copper bar stock rather than swaged or extruded like most bullets. It says “Extreme” right there on the box so it must be something special, right? It has also produced some interesting results in testing and a lot of people are very excited about it. The company is making some quite literally incredible claims, though.

When compared against FMJ in the same weight, the 9mm version did penetrate “extremely”. To this date, there doesn’t appear to be anyone with enough gel on hand to capture the bullet in the gel but this test managed to capture it in water jugs backing 30” of calibrated 10% gelatin. After passing through the entire 30” of gel, it penetrated an additional 30” in water jugs. The latter should correlate to roughly 18” in gel or tissue for a total penetration of approximately four feet.

That is astounding penetration for a 115 gr 9mm projectile. The 115 gr FMJ, which was moving about 100 fps slower only penetrated to approximately 27” before leaving the block at a low enough velocity that it was recovered lying on the ground beside the block. The FMJ did create a larger wound channel when it yawed, though.

The results in .380 are a little different. The Lehigh bullet did not penetrate extremely. It was beaten out in penetration pretty handily by the FMJ. But there was also some surprising disruption in the gel that is not seen with FMJ.

The lower penetration is actually a good thing for a defense load, though. It is, of course, necessary to meet the minimum recommendation of 12”, but it is not useful to exceed the maximum recommendation of 18”, which all of the FMJ bullets did by a significant margin. Still, the “Extreme Penetrator” does not live up to its name in this series of tests.

There is a great deal of talk going on about what appears to be some extra disturbance in the gel created by the Extreme Penetrator in this .380 test. There is no argument that the “wound channel” left behind the Extreme Penetrator does show wider disruption in the gelatin. While it certainly appears to be causing a little more damage this is not necessarily the case. It is not actually any wider than a .380 FMJ because it obviously does not expand. At that velocity, the only way to cause permanent damage is by direct crushing and cutting of tissue.

What we are likely seeing in the gel is a little extra temporary stretch cavity, which does not increase the size of the wound in any significant way. It is possible that the sharp edge of the nose cuts tissue a little better than a rounded profile nose but if that were the case, we would expect to see a similar effect in the 9mm test above. There are many opinions floating around on this issue and as of yet, no one has sufficiently proven one way or the other whether there is actually any more tissue damage created by this projectile.

The 10mm test showed similar temporary stretch cavity but still only penetrated about 26”, which is not particularly impressive for a 10mm solid. On the other hand, 140 gr is light for caliber and the bullet did maintain its forward orientation just as seen in the previous tests. Moreover, we seem to see that extra cavitation again that was seen in the .380 test but not present in the 9mm test. Perhaps the effect does have something to do with a short, low sectional density bullet.

It was also able to penetrate a Level IIA vest, which is rated for 158 gr .357 magnum fired from a short barrel so perhaps it lives up to the “Extreme Penetrator” name in some way. That said, a 140 gr FMJ might have penetrated the same vest.

As a company, Lehigh is fiercely defensive of their reputation and will refuse to provide test and evaluation samples without assurances that the “testing” will portray their product in a positive light. This leaves us somewhat suspicious of reviewers that are known to use samples not purchased with their own funds.

Although it was originally billed as a penetrator, they were quick to embrace the idea that the Extreme Penetrator causes some additional tissue damage over a similar FMJ and have not only added that claim to their marketing, but embellished it a bit. They skip right past any speculation about temporary stretch cavity and go straight to the audacious claim that it creates “…a permanent wound cavity diameter exceeding that of most expanding bullets.” (http://www.lehighdefense.com/pages/xtreme-penetrator)

Yes, you read that right.

They are claiming that the Extreme Penetrator causes a larger permanent cavity than jacketed hollow point ammunition. This is demonstrably false, of course but let us pause for a moment to remind readers that permanent cavity in a wound caused by a pistol bullet refers to tissue that was directly crushed or cut by the projectile as it passed through. Except in the unusual circumstance that a JHP fails to expand, it will always produce a larger permanent wound cavity than the Extreme Penetrator.

If you are unsure of that, please take a moment to review a few of the tests in these 9mm and 10mm playlists:


It might be reasonable for Lehigh to have speculated about increased performance over FMJ. The .380 test certainly hints at that. It is patently ridiculous to claim that the Extreme Penetrator creates a larger crush cavity than JHP, though.

The product does appear to do an excellent job of preventing yaw, which has a negative effect on penetration. That appears to help it penetrate more than a traditional bullet in the same weight, sectional density, and velocity. It is easy to dismiss that part but it is the core of what this bullet was designed to do.  It is widely known that FMJ penetrates pretty deeply, but as we saw in the 9mm test, it does not usually travel in a straight path. The reason is that bullets are heavier in the rear than they are in the front. The spin imparted by the rifling in the barrel is more than adequate to stabilize the projectile in air, but it is suddenly no longer adequate in tissue, gel, or water, which are far denser. Water is 784 times as dense as air at sea level.

That extra density causes the bullet to yaw 180° and continue its travel with the base forward. The base is less streamlined, though, and the bullet has to travel sideways for a distance while it is yawing, which both increases drag and reduces penetration. The yaw also usually results in a deviation of the bullet’s path.

For whatever reason, the Extreme Penetrator’s design allows it to remain nose forward throughout its entire journey through the gel. It certainly could be deflected by a bone like any other projectile but the ability to maintain its orientation allows it to penetrate much more deeply than one would expect based on its weight, sectional density, and velocity alone.

It does another thing exceedingly well. It separates shooters from their hard earned dollars. It sells for $30 for 50. 50 bullets, that is. Loaded ammunition is significantly more expensive. Is it worth the extra cost when compared to FMJ or heavy cast bullets? Possibly, but only in very narrow circumstances. When it comes to actual measured performance, it does penetrate better than FMJ in some cases.

If one insists on using a 9mm pistol or carbine for woods carry, it could offer the extra penetration needed for large animal defense. If you are looking for the right ammunition to load your Glock 17 with on your next shark hunt, it might be just the ticket. For normal human defense, or even for large animal defense in a caliber better suited to large animal defense, there are better options that cost less.

Andrew Betts served with the Arizona National Guard for over 12 years, including a tour to Afghanistan.  Visit his YouTube Channel for more great shooting information.

Photo credit – Leigh Defense

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