Which will give the most penetration.

Energy isn't a predictor of penetration.

Momentum, sectional density, and bullet construction are the main places to look for a rough idea.

And then actual testing to confirm.

.22lr is quite likely to penetrate further than .380, especially out of a pistol, because the .22's velocity is often insufficient to cause expansion. Many .380s don't expand well either, but I would not be surprised if most .22lr penetrates further than most .380s.

I think that if you compare FMJ .380 ammo with a fully-jacketed .22LR such as the CCI mini-mag copper-plated solid, the .380 FMJ will probably have more penetration than the .22LR. I have seen ballistic gel tests that show solid .22LR with around 16" of penetration. Most fragmenting or hollow point .22LR will usually have less.

Most .380 ammunition has twice the mass of the .22LR projectile so the linear momentum of the projectile is going to be greater than that of the .22 despite the lesser muzzle velocity since the muzzle velocity of all reasonable .380 loads is well over half that of the high velocity .22LR loads.

But what do you want to use a .380 revolver for? I know many will disagree, but I would avoid that cartridge if you are interested in using it for self-defense. Many who do rely on .380 Auto for SD use FMJ loads to insure good penetration since many .380 JHP loads fail to expand, or fail to do so reliably, and when they do expand the penetration is usually less than desirable.

Here is a good ballistic comparison of various .380 loads:

http://www.luckygunner.com/labs/self-defense-ammo-ballistic-tests/#380ACP

You can see that the heavier .380 loads that did not expand had up to 25" of penetration whereas the loads that expanded consistently tended to have inadequate or barely adequate penetration from a SD standpoint.

380 ball will destroy a 22 in penetration from a pistol .

As for 380 HP Iam not in FBI and FBI didn't test the 380. That number is for the caliber they wanted 40. Now their dropping back to the poor old 9mm again. Funny another govt. law enforcement Who really gets in gunfights says 10" is ok
. Iam not going to shoot thru car bodies ,windshields, door walls and every thing else the FBI does. When they really do shoot . I will be using my 380 up close and personal . I feel 9 or 10 Inches The HP will work Not just going to shoot 1 time and stop.

Penetration is enhanced by
1. Velocity at impact
2. Diameter of projectile, and
3. Shape and material.

Which has nothing (very little) to do with 'power' or defensive utility.

However, if one is planning on getting in a 'penetration' competition, I'd choose a custom built pistol in 7.65 Tokarov with a really long barrel and special made bronze spire point bullets. And a hot load.

So, Hunter; what are you seeking or are you just curious?

There are ways to calculate this, typically with the Poncelot equation.

Check the table on Chuck Hawks website. A 380 fmj penetrates something like 17" and a 22 rf rnl does 24" in ballistic gel.

There are a quite a number of tests showing 380 FMJ zipping out the back of 18" blocks of ordnance gelatin. Also quite a few tests that show the 380 FMJs going 21" to 24"

https://www.youtube.com/watch?v=YbSLqdiX_bA

Ball .380 is known for over penetration...so, it will outperform .22.

Do a google search for NATO Handbook on War Surgery. Go to the chapter on Missile Caused Wounds authored by Col Martin Fackler MD who was Chief of the Army Wound Ballistics Lab, Presidio, Calif for a in depth discussion on this.

Facklers work determined several things:

1. In order for a hollow point to expand reliably it must impact at 1150 fps range.
2. For effective penetration it must be capable of entering the body and leave a significant wound tract.

3. A 357 Mag 125 gr. Remington did well in his testing. Even better was the 357 145-158 gr. and heavier bullets were effective.

4. His work was the basis for the 10MM as he determined the min bullet energy was 185 gr bullet at 1150 FPS.

5. His personal carry gun was chambered in 45 ACP w/ 230 gr. FMJ.

6. About the only 9MM that will obtain the penetration required is the NATO 9MM which is much hotter than US commercial loadings. Only problem is most 9MM handguns won't take it day in and day out. In 9MM testing I was involved with at Aberdeen Proving Ground 9MMs went down about 6000 rounds. The first Aberdeen test I was on was for a 10,000 round life and NOTHING MADE it.

7. There were designs that are known to take it but they were not tested as they were not double action. Browning HPs, Rugers, Glocks, Colt Gov't Mod 9MMs, will take a it. There might be more but they are the only ones I can recall off hand.

8. Fackler told me he also evaluated the round the FBI dumped in favor of the 9MM and it was superior insofar as penetration was concerned. The round the abandoned was 38 Special with 200 gr. lead bullets.

Facklers work determined several things:

1. In order for a hollow point to expand reliably it must impact at 1150 fps range.

4. His work was the basis for the 10MM as he determined the min bullet energy was 185 gr bullet at 1150 FPS.

6. About the only 9MM that will obtain the penetration required is the NATO 9MM which is much hotter than US commercial loadings.

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There have been significant changes in bullet design and these assertions are no longer true. It can be shown both in testing and in real world shootings that there are 9mm designs out there that travel under 1150 fps, do penetrate to 14 and 15 inches and expand in the .64 caliber range, and result in consistent and acceptable stopping of perpetrators / suspects by police in field use. The 147gr Winchester Ranger "T" Series and the 147gr Federal HST are just 2 examples of this.

1. In order for a hollow point to expand reliably it must impact at 1150 fps range.

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Unless you can tie this number to a specific make and model of bullet, it is nothing more than a random number. There are a lot of "hollow points" out there today, and each has its individual best velocity ranges for expansion.

Talk to emergency room surgeons. They will tell you that while the .22 does penetrate, it doesn't penetrate straight. I know of at least one case where a man was shot in the chest by a .22, and the bullet came out his back -- but never entered the chest cavity. It deflected on the breast bone, went along the ribs, deflected again at a vertebra, and came out the man's back.

Posts 13 and 14 said exactly what I'm going to repeat. There was a time when even the 9mm was marginal (or less), due to bullet construction. However, we've got hollow point bullets now that are designed to work in a given diameter, at a given velocity and expand to a given end diameter. Of course nothing is foolproof. But we are light years ahead of even two decades ago. I used to steer people away from the 9mm, but not any longer. It's a completely adequate cartridge now when loaded with JHP.

The number throw around by Fackler used to be true. Bullet design, however, has rendered this part, at least, of his work invalid. .45ACP Federal Hydra-Shok, for example, is designed to expand the hollow point bullet at well below the 1,150 FPS target. MV is a published 900 FPS and the round has held up to testing quite well.

However, if one is planning on getting in a 'penetration' competition, I'd choose a custom built pistol in 7.65 Tokarov with a really long barrel and special made bronze spire point bullets. And a hot load.

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I agree! I love 7.62 Tokarev. It's an impressive round. Fast, soft recoil, accurate, low trajectory. Now if someone would only make a modern pistol in it, that'd be awesome. I don't see why a manufacturer couldn't make a 1911 in 7.62 Tokarev. Besides, the 1911 is very similar to the M57/TTC/Tokarev design, but more ergonomic.

ATLDave said:

Energy isn't a predictor of penetration.

Momentum, sectional density, and bullet construction are the main places to look for a rough idea.

And then actual testing to confirm.

Click to expand...

Those and target density and composition.