This is the second of my three-part series on evaluating the terminal performance capabilities of the GLOCK 42. In Part 1, I determined that the G42 (when using the ammo that won my .380 Ammo Quest) delivers enough penetration and expansion to meet the FBI minimum penetration threshold for ammo performance. The GLOCK 42’s longer barrel meant that the ammo expanded more and penetrated a little less than it did from the 2.8” barrel of a Taurus TCP. But the overall penetration was still in excess of the 12″ minimum requirement . . .
In my original .380 Ammo Quest, I found there were several types of ammo I fired from the TCP that just didn’t perform consistently. Sometimes bullets would expand, sometimes they wouldn’t. One example in particular was the Buffalo Bore 90-grain JHP (item 27G/20). Three of the rounds expanded nicely and penetrated fairly well. Two didn’t quite meet the 12” standard but they came close. However, two of the rounds failed to expand and grossly overpenetrated, so I ruled the Buffalo Bore 27G out of contention for use from a 2.8” barrel.
My assumption was that the 2.8” barrel was delivering velocities just a little too low to ensure reliable, consistent performance. But the GLOCK 42 may be a different story. It has a barrel that’s almost a half inch longer than the TCP’s at 3.25”. Would the additional velocity from that longer barrel be enough to turn the Buffalo Bores from an also-ran into a serious contender for daily carry? Only one way to know. I set out to the range with some ClearBallistics gel, a chronograph, and the G42.
The results were a classic case of good news/bad news. The good news is that yes, indeed, the G42 delivered additional velocity (an average of 1016 feet per second, vs. 937 fps from the TCP). And yes, that velocity increase puts the Buffalo Bores above the threshold for consistent expansion and performance. All five test shots expanded to a huge diameter (for a .380). It also means a big bump up in kinetic energy. The TCP produced about 175 ft/lbs with this ammo and the 42 produced 206 ft/lbs.
That was the good news. The bad news is that while we got consistent expansion and performance, the bullets spent that additional energy on expansion rather than penetration. In fact they ended up penetrating even less than they did from the TCP.
The performance was very consistent, much more like what we want to see. But the penetration came up well short of the 12” minimum that I greatly prefer ammo to accomplish. That said, 10” isn’t bad, it’s just not quite deep enough to ensure that the bullet can hit vital organs from any angle or through an intervening arm. But if you’re taking a straight-on shot, yes 10” is enough.
I prefer the minimum of 12” (as determined by the FBI) because in a self-defense encounter, you don’t get to pick and choose your shots. You can’t just stop the gunfight and ask the attacker to please turn toward you with his arms out to his sides to ensure that you get a nice, clean shot at his chest. For those reasons, I prefer ammo that reaches at least 12” through ballistic gel.
So how could the results have been actually shorter penetration, from the longer barrel? The answer lies in the expansion.
The Buffalo Bores expanded magnificently, growing to a five-shot average size of well over half an inch (.516”). That’s quite a bit bigger than the .472” of expansion from the TCP. But the larger the bullet, the more drag it exhibits. It takes more energy to push that larger bullet through the body tissue. And that’s where all the additional kinetic energy went – into expansion and into trying to push that bigger bullet through the body.
GLOCK 42, 3.25” barrel Taurus TCP, 2.8”-barrel
Kinetic energy 206 ft/lbs 175 ft/lbs
Velocity 1016 fps 937 fps
Expanded Diameter .516” .472”
Penetration 9.90” 11.33” (but 2 failed to expand)
My hope was that we would have gotten the same expansion, and that the additional kinetic energy could then have been used to push that bullet deeper. But that’s not what happened; instead we got bigger expansion, but shallower penetration.
My final conclusion then, is this: the Buffalo Bores were a good, but not great performer from the GLOCKk 42. They definitely performed more consistently than they did from the TCP, and if I had to choose a gun to use them from, I would choose to shoot them from the G42. But they didn’t meet my standards for penetration. So while they were more consistent and the G42 was able to make them perform better, it’s clear that careful ammo selection remains just as important with the G42 as it is with the smaller pistols.
The .380 ACP is a challenging caliber from which to get proper performance. There’s too much energy for FMJs (they overpenetrate far too much) but there’s not quite enough energy to make most hollowpoint rounds perform well. It’s a tricky dance the ammo designer has to do between expansion and penetration to achieve a good overall performer.
I would still recommend a smaller-expanding bullet for use with the Glock 42, to ensure sufficient penetration. That includes pretty much any load that uses the Hornady XTP bullet (examples include Hornady Custom, Fiocchi Extrema, HPR, Precision One, Underwood, Wilson Combat, and others) or perhaps the Federal Hydra Shok. All of these performed quite well from the TCP, and the Precision One loading of the XTP performed best in Part I of this series. If you’s rather get your ammo from a bigger company and a bigger brand name, I would recommend Fiocchi Extrema or Hornady Custom.