Underwood Xtreme Defender Follow-up

I recently tested Underwood Xtreme Defender 9mm ammunition provided by Ballistics By The Inch, a website dedicated to testing ammunition. The results were intriguing. In gel tests penetration was good and the permanent wound cavity showed significant disruption of ’tissue’ along the length of the track. Very promising on ‘on paper,’ but I and others have had questions about how it would perform in the real world of bone, gristle and other body structures.

Underwood Xtreme Defender ammunition used a monolithic copper/light-for-caliber round configured to both penetrate and disrupt tissue with hydraulic forces.

During discussions of my tests we all agreed that some sort of real-world test was needed before passing judgement on these bullets. As it happens I have a friend in Texas, which is suffering under a veritable plague of feral pigs. In addition to wreaking havoc on crops these creatures represent a legitimate threat to human beings, even to the point of attacking, killing and eating them. Mike regularly has to kill these creatures, and agreed to test the Xtreme Defender on them should appropriate circumstances occur. BBTI sent him some ammunition for the test, and we didn’t have to wait long for a report.

The pig was shot and crippled with a rifle, then finished with the 9mm ammunition. Mike is indication the wound from the pistol bullet with his knife.

“Was able to pop a moderate sized wounded sow last night with a Defender. She had been knocked down and got up to flee when we walked up on her. IMO this is a good and valid test, as adrenaline and the urge to flee is about as high as possible. The bullet cleanly broke a rib and penetrated about 6-8 inches. The wound track showed considerable tissue disruption for the full depth of penetration. At the hit, she went down and stopped all attempts to do anything. She just breathed a few breaths and was dead.”

‘That’s not enough penetration!’ I hear you cry. Isn’t it? The FBI standard is 12-19″ of penetration in ordinance gel after passing through four layers of 16 oz. denim, but the thing to remember is that this doesn’t represent penetration in an actual human body; it is a comparative tool only. The reason for the depth specification is because real bodies contain bone and other variable-density structures that can reduce the bullet’s penetration. The 12-19″ standard takes this into account; in absolute terms a bullet needs much less penetration than that in a body do cripple vital structures.

I’ve read several accounts of wounds left in medium game animals by 9mm 115gr. JHPs, and this performance appears comparable to those accounts. I’m usually skeptical about light-for-caliber high velocity bullets for self defense, and both testing and real-world results seem to bear that out. But these bullet’s differ in both design and wounding mechanism compared to conventional bullets, and it seems to work. They are also immune to ‘loading up’ with fabric etc. as can sometimes happen with hollow-point bullets.

That being said there is no such thing as a ‘magic bullet.’ The only way to produce a ‘hard stop’ with a handgun is to break things the baddie can’t function without, and these don’t change that fact. You still need to do your part by getting the rounds on target, and to hit things that matter like the central nervous system and circulatory system. No bullet will do the work for you. With that caveat I have to say I continue to be intrigued by these bullets, and I strongly suspect that they will do the job as well as conventional hollow-point ammunition.

The only way we will know how these perform in self-defense shootings is if enough of those happen that we have a large pool of evidence, a circumstance that I honestly hope never occurs. Comparative tests are likely to be the best measure we’re going to get, and in our tests and others these bullets seem to perform comparably to other defensive ammunition in this caliber, with some potential advantages.

In my testing they have been accurate, they are low recoil and work reliably in my weapon. The low-mass of the projectile means it will have poor penetration of household obstacles like walls and appliances. With that in mind I would be confident in loading them in my ‘night-stand’ gun for self-defense.

More testing is in the offing, and I’ll follow up as more information becomes available.

Take care and stay safe- and Happy Independance Day!

Michael Tinker Pearce, 4 July 2021

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