Handgun ammunition comparison?

Old 02-08-17, 04:39 PM
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Handgun ammunition comparison?

I came across this handgun ammunition comparison. It's a great article but something seems odd to me.

They tested various ammunitions by shooting them into ballistic gelatin and measure the penetration depth and the diameter of the expanded projectile. The .380 chart shows the Hornady 90g FTX Critical Defence penetrated an average of 13.2" and expanded to .52" with an average muzzle velocity of 910. So far so good....

In the next chart for 9mm ammunition the 115g Hornady Critical Defence penetrated 13.1" and expanded to .50" with a 1'143 muzzle velocity. So, both bullets start out the same diameter but why is the lighter one from the .380 penetrating deeper and expanding more? The .380 is about half the power of the 9mm. In general across their tests the .380 seems to perform better than expected.
Old 02-08-17, 05:00 PM
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Just a WAG, but could it be from the slightly more streamlined .380 during its initial trip out the barrel, actually moving more aerodynamically, even at a lower FPS than the 9mm, and once it hits the gel, the performance differences are similar.
Old 02-08-17, 05:19 PM
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The .380 is about half the power of the 9mm.
How do you figure? .380 muzzle velocity is only 233 FPS slower then the 9mm. That is only about 20% less then the compared to the 9mm. The barrel lengths of the guns used were only 1/4" difference so I would not expect much increase in velocity but you never know with firearms. The longer the barrel, the more speed the bullets will get which also could affect results.

I just skimmed the article for this reply. I am going to sit down and read it fully on my tablet. Thank you for posting it!
Old 02-09-17, 04:25 AM
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Don't forget you have to factor in bullet weight as well. On avg, a .380 is around 200ftlbs or so and a 9mm is around 390. Of course, I don't know exactly what weights they were using as they just said "with the most common bullet weights for each caliber". I would imagine that would be 90 gr and 115 gr (maybe 124 gr?) respectively or possibly they averaged between the top big sellers?

As to the original question, it's all about bullet design and metallurgy nowadays. Why manufacture something that shoot's all the way through using the same design as a smaller caliber or conversely doesn't meet the minimum standards using the design of a larger caliber?

Just because both boxes say "Critical Defense" does not mean they use the same bullets in a different size. Look at the 124gr Critical Duty vs the 115 Defense. Slower, massive penetration, less expansion. Different job, different design. Even stranger, look at the Duty 135 vs the 135+P. The +P must work better right? Nope...

Here's an older study and their results don't match your link. https://www.americanrifleman.org/art...-your-options/

I still use my remaining supply of original Hydra Shok and Starfires in my .45s and .380s. They both shoot to the same point of aim as FMJ so practice is a bit cheaper. Luckily no one has had reason to complain.

Side note...I was reorganizing my ammo a few weeks back and some boxes of 20 still had stickers on them. Try to find .45 HS for $14 or .380 SF for $10. Just makes me weep when I see where the prices are now. I know you can order it cheaper than off the shelf...but it's still not cheap at $1.20 a round
Old 02-09-17, 08:35 AM
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It's just interesting that they got nearly the same penetration and expansion out of two bullets with such a difference in energy. I know bullet design has come a long way but that's almost incredible. I wonder if the .380 expands more slowly to aid penetration while the 9mm opens sooner and relies on it's greater velocity and mass to maintain penetration.
Old 02-22-17, 06:07 PM
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... I wonder if the .380 expands more slowly to aid penetration while the 9mm opens sooner and relies on it's greater velocity and mass to maintain penetration.
That's the only possible explanation. The .380 started out with 26% less velocity and 28% less weight, which figures to almost exactly half the 9mm's FPE (166-vs-334). In Newtonian physics, there's no way you can do more with less. There is no free lunch. The 9mm experienced no significant loss of mass (else they'd have so noted), and the only other way to explain the .380 penetrating to the same depth (+/-1%) despite expending less KE and less momentum (and still satisfy Newton) is to figure it took more time from the instant of impact for it to stop.

The 9mm undoubtedly slammed on the brakes sooner and the .380 held off on the braking until the last moment. If that was because Hornady deliberately designed that bullet to meet the FBI's 6-protocol standardized test, I'd count that a very good thing. That test itself probably is the one good thing resulting from the disastrous 1986 Miami shootout.

But (and I'm speculating that that is in fact the case, since the .380 tends to be lacking in either penetration or expansion, and this load has both in spades) you have to wonder why they'd go to the trouble for a "mere" .380. Maybe it's because the sales boom of the last eight years left them so flush with cash it was either invest in R&D in some of the lesser cartridges or give it over to the tax man. Or maybe it's because of the .380's recent revival, or maybe they've found that enough shooters are paying attention to the labels now that being able to advertise "Meets FBI standard" more than pays for expense of the tests.

Especially interesting because Hornady's Critical defense line hasn't always fared so well on the FBI test.

Back in the olden days, you couldn't sell a PC running Windows unless it either was an IBM or it was labeled "100% IBM-compatible." Maybe "Meets FBI Standard" is the new "100% IBM-compatible" for handgun ammunition.

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