Underwood Xtreme Defender 115gr Versus Level IIIA Armor

[Intercooler]

[Intercooler]

I had the one slow reading of 1607 FPS skewing my 4.75" results some. Looks pretty much like expected from the 4.5" barrel!

[The_Shadow]

Yes it is an interesting bullet...expensive being solid copper and cut on a CNC one at a time!
Yep it defeated that soft armor...not all soft armor is the same either.

[4949shooter]

Good video from Chopping Block.

I agree the hollowpoint is always a better choice for personal defense. Though, in areas where hollowpoints are not permitted (NJ), this is a viable option to my way of thinking.

As to his comments at the end, I have mixed feelings on the posting of these body armor penetration videos. On the one hand, I fully agree that information is there for the taking, and it is up to good or evil to use it as such. On the other hand, as a law enforcement officer I wouldn't post this information on a public forum due to concern it could fall into the wrong hands. This topic is a doubled edged sword.

I'm not condemning ChoppingBlock for posting it. If I weren't a law enforcement officer I'm sure I would feel differently.

[Intercooler]

   It was sent through armor before by other YouTube channels prior to this test. In a way I kind of like knowing what will go through certain armor. I think back to Aurora and a couple of ifs... if a CCW had these loaded in the magazine at the time, the armor he was wearing wouldn't have saved him. The other side of the coin is maybe an armor company would see it and make improvements to stop it. One thing is for certain and that is if anyone is looking to really defeat armor their are tons of rifle rounds.

[Big10]

I've heard this bullet described as a "gimmick", noting that ballistics gel doesn't stretch like real tissue. And this video makes the same point by saying a JHP will make a bigger permanent wound channel/cavity and the flutes are not really working as advertised.

If gel is not an appropriate medium to represent the effect of "permanent wound channel", how then do they determine the size of permanent wound channels to base this statement on?   

In all the reviews of this type of bullet (Lehigh Xtreme Defender bullets, not cartridges) I've never seen any that attempt to measure the "permanent wound channel".  In fact, in all YouTube jello research, testers do nothing more than to look at the jello carnage and draw conclusions. So if ballistics gel isn't the proper medium on which to base the claim that the flutes work, it is also not the proper medium to disprove that flutes work.

[The_Shadow]

The Xtreme Defender 115 has a smaller cross section of the cross of the 140 grain Xtreme Penetrator...velocity being the part of the factor that drives the performance...


The Lehigh Defense 115 Xtreme Defender from Underwood
http://10mm-firearms.com/factory-10mm-ammo-pull-downs/underwood-115gr-lehigh-defense-xtreme-penetrator-(100-solid-copper)/msg62479/#msg62479

The Lehigh Defense 140 Xtreme Penetrator from Underwood
http://10mm-firearms.com/factory-10mm-ammo-pull-downs/underwood-140gr-lehigh-defense-xtreme-penetrator-pull-down/msg37134/#msg37134

[Big10]

Right, but the claim being tested is whether the flutes work as advertised.  Nothing to do with the cross.

[The_Shadow]

Big 10, I understand that the cross is not the flute, but it does add to the piercing penetration, as the spiraling of the projectile causes a cavitation of sorts, that is lead by the cross points and then wedged outward as an expanding bubble, dissipating and dumping energy.  So I'll add this as consideration and study...

The rotation of most 10mm handguns are 1:16" but a Glock is 1:9.84"  Why do I mention this?
Bullet RPM Formula
Here is a simple formula for calculating bullet RPM:
MV x (12/twist rate in inches) x 60 = Bullet RPM
115 gr Xtreme is 1700 fps, plugging that in, equates to;
124390 rpm at the muzzle of a Glock 1:9.84 factory barrel
76500 rpm for a standard 1:16 barrel barrel

[Big10]

Shadow, to be clear, I'm not arguing against the points you raise and agree with them.

What I'm asking is how do the reviewers make the claim that the flutes don't work?  They explicitly say that you can't look at the gel trauma to determine their effectiveness.  But then what do they look at to say JHP actually performs better "in most circumstances" (taken from the video in the OP)?

I mean, all they have are the gel results they just shot. But then we're supposed to ignore them, unless they are JHP bullets?

[The_Shadow]

I agree with what you are saying, and they also say that real gel is more realistic than the synthetic clear gels. but they both tend to have similar results. They stretch, tear and cut but they are not actual skin, fat, muscle, lung or bone tissue.  Most body organs are hollow organs, stomach, lungs, guts, bladder and semi solid organs like liver, spleen, kidneys, heart and brain.   No matter what we shoot, bullet placement remains the key issue.  What is impacted and acted on with the energy that is transferred to those tissues determines the level of damage.

The nervous system such as brain, brainstem and spinal cord require lots of energy to shut down or be severed.  Heart and lungs (larger target), arteries and veins (smaller items) are usually a larger blood loss event and can take 4 to 6 minutes to cause incapacitation and or death.  Skeletal bone structures that are broken or shattered may immobilize a person or animal but will just likely slow it down.

The gel standards are nothing more than a study from a media that has repeatable results.  Many animals and people have died via wounds from pure lead projectiles...round balls and shaped or cast projectiles before jacketed bullets became a norm eliminating lead fouling and allowing more shots between cleaning in rifled barrels.

Then there are the FMJ non expanding type projectiles, some of which were designed to upset and tumble upon impact destabilization that increased their effectiveness.

No matter what, I wouldn't want to be hit by any projectile...because a two cent bullet can kill ya just a fast as a five dollar bullet.

[coat4gun]

The theory that I have been tossing around in my head s that the flutes act much like a pressure washer accelerating high speed fluid in a direction perpendicular to the bullet path. I have seen pressure washers cut skin. Imagine what it could do to much more fragile lung tissue. I am sure that someone with some advanced math could calculate the speed of the fluid that is generated by a projectile traveling at 1200+ fps through a fluid. Thats how I believe it creates such an extreme wound channel.