Since finishing and posting my article on overpenetration, and why so much of the worry about overpenetration is simply overblown, it’s brought me back to the subject of full metal jacket bullets (aka “FMJ’s”, usually used strictly as “range ammo” or “training ammo”).
FMJ’s For Self Defense?
FMJ’s are not generally recommended for self defense purposes, as they’re really rather ineffective as compared to modern hollowpoint ammo. An FMJ is really just a hunk of lead, sheathed in copper; when it hits a target it pokes a hole in the target, and that’s really about it — there’s no expansion, no big temporary wound cavity to speak of, it’s pretty much the simplest and least effective bullet design for causing wounds.
Now, don’t get me wrong, FMJ’s can certainly kill, and they can cause critical hits if they happen to hit the central nervous system or a major artery or the heart. It’s not like an FMJ won’t do damage, it will, it’s just that — well, just about any other kind of bullet will do more damage than an FMJ would. The FMJ is the least damaging type of projectile in common use. A wadcutter is a much more effective wounder than an FMJ, and a hollowpoint can be a significantly superior wounder than an FMJ (assuming, of course, that it penetrates deeply enough).
That’s where FMJ’s excel — penetration. Because they’re basically a round-nose, slippery design, they present a very low-drag profile and they slip through tissue (or air or water or whatever) easily. And because they slip through tissue so easily, FMJ’s present a very real prospect of overpenetrating. Even in a relatively weak caliber like .380 ACP, an FMJ will easily be able to penetrate 22 to 25 inches of ballistic gelatin — and anything over 18″ is considered an overpenetrating bullet. That’s another reason why, in contrast to some other terminal ballistic experts, I consider FMJ’s a poor choice for the .380 — they provide weak wounding and high overpenetration dangers. They’re unquestionably a better choice than an underpenetrating bullet would be, but I’d much, much rather use a properly-engineered hollowpoint that penetrates deeply and avoids overpenetration and has an aggressive wounding profile, than use a slippery little FMJ that will sail right through the attacker, causing minimal damage as it goes, and still presents a potentially significant threat to anyone behind the attacker.
How much of a threat is an overpenetrating FMJ?
Let’s consult Charles Schwartz’s excellent Quantitative Ammunition Selection to find out. In my previous article I had demonstrated that a good .380 or .45 ACP hollowpoint, after penetrating through 9″ of an attacker’s torso, wouldn’t likely have enough residual velocity to even break the skin of a person standing behind the target. Even if the bullet overpenetrated, it would still have enough energy to cause a nasty bruise, sure, but it wasn’t likely a significant risk to still be lethal; the journey through the attacker’s body would slow the bullet down below 300 feet per second, rendering it unlikely to be able to even break skin. Applying the same formula and calculations to an FMJ, we get very different results — frightening results. A 90-grain .380 ACP FMJ, for example, would travel at about 900 feet per second from the muzzle. After penetrating through 9″ of muscle tissue and exiting out the other side, it would still be traveling at 385 feet per second — and that’s enough to penetrate almost 8.75″ of ballistic gel! And that means that while it doesn’t exceed the FBI/IWBA minimum 12″ penetration depth, it could still easily cause serious damage or even possibly a fatal hit on a bystander.
Of course, the story is much worse with the .45 ACP FMJ. Using a 230-grain projectile at 850 feet per second from the muzzle, it’d penetrate through that 9″ torso and when it overpenetrated it’d still be going 498 feet per second. That would give it enough energy to be able to penetrate over 16″ of ballistic gel, definitely capable of a fatal hit. But let’s put it in perspective — let’s say that the .45 ACP FMJ penetrated through the 9″-thick attacker, and continued on to hit a bystander — at 498 feet per second, it’d have enough energy to easily pass completely through 9″ of bystander, and still be going at 252 feet per second! After exiting the bystander, it’d still maintain enough energy to reach almost 8″ deep into ballistic gel — again, far enough to cause serious damage, and depending on where it hits, it may even cause a critical/fatal hit on a person behind the bystander behind the attacker. Yes, one .45 ACP FMJ could pass completely through two people and lodge deeply enough in the third to cause a fatal hit.
Is overpenetration a concern?
Yes, but it’s only a significant concern if you’re foolish enough to load your defensive weapon with FMJ bullets instead of hollowpoints. If hollowpoints are legal for self defense where you live, USE THEM. They’re much more effective wounders, they’re much more likely to stop an attacker, and they vastly minimize any risk of overpenetration. A hollowpoint expands so large that it slows down dramatically while it’s traveling through the attacker’s body; even if it overpenetrates it’ll be going so slowly that it won’t be nearly as dangerous as an FMJ would be. The only time I’d recommend against hollowpoints is when you’re using a tiny caliber (specifically .22LR, .25 ACP, or .32 ACP) where there just isn’t enough energy available to push a hollowpoint deep enough to cause a critical hit — in those cases, you have to go with a non-expanding bullet; wadcutters would be preferred, but use FMJ’s if you can’t get wadcutters. And in .380 ACP, careful ammunition selection is vital — some hollowpoints grossly under-penetrate and can leave you at risk; you have to choose a hollowpoint that penetrates deeply enough to have a chance of causing a critical hit, while minimizing the risk of overpenetration. See my articles on the .380 Ammo Quest for test results on ammo that can achieve this goal. And for any caliber more powerful than .380 (such as 38 Special, 9mm, 10mm, 357 Magnum, 357 Sig, 40 S&W, 45 ACP, or 45 Colt) there’s no question — for safety and effectiveness you should be using hollowpoints, and avoiding FMJ’s, for defensive purposes.
Interesting work
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I agree, don’t worry about it, but do be aware of it. It was a factor in NYPD’s finally getting JHPs finally approved for issue to everybody in 1998. In just two years (95/96), 41 of the 121 people hit by NYPD bullets were hit by NYPD bullets that went through somebody else first. 36 were hit by FMJ, 5 by JHPs. 23 of those were bystanders and other cops (22 FMJ, 1 JHP). 18 were suspects (14 FMJ, 4 JHPs). Source is a NYT article about the1997 SOP9 report.
Hi there. Really great stuff on your site. I appreciate all the work and thought that went into it.
One question though. I may have missed it, but do you have any thoughts about using flat nose fmj or flat nose hardcast in a .380? It seems to me they would have significantly less chance of over penetrating, while getting better penetration than hollowpoints, e.g., 16 inches (the few tests out there seem to corroborate this). Currently I alternate standard pressure Underwood hardcast flat nose with Federal Hydra-shok hollowpoints.
Many thanks,
David
I have tested flat-nose FMJ (Winchester White Box) and got huge overpenetration from it. Two shots ended up at 26.50″ and 27.75″, which was even further than the round-nose FMJs went (they went 23.00 to 24.75″).
There’s a new option out there, however, which might be a much better choice — it’s a flatnose solid copper bullet that features some cuts and grooves in it that the manufacturer claims will greatly increase the size of the wound channel, while bringing penetration down into the acceptable range (they say 17.0″). Sounds ideal, and I’m going to try to get ahold of some for testing. If it really does perform the way they say it will, it might be the ideal round for a .380 pocket pistol.
You may want to factor in the offside skin stretching after penetrating a body. Which is the reason that a lot of bullets end up on the other side of the animal or human just under the skin. You can test this by using an icepick or screwdriver to poke a hole in a piece of meat packaged in plastic. The 1st layer of plastic is defeated easily but when the icepick reaches the other side the plastic stretches and it is more difficult to penetrate it. Secondarily, is there much evidence of this even being a problem in shootings? How many people have been hit by a projectile after it went through a person’s torso? If I remember correctly, Massad Ayoob gave the wrapped meat example somewhere.
Getting through the stretched skin of the far side can be equal to another 4 inches of muscle. Why bullets are often recovered just under the skin and/or clothes on the far side. Two USAF were playing quick draw on post when one was shot w .38 Special FMJ. The bullet was recovered just under the guard’s outer jacket on the far side, after penetrating the jacket, shirt, t-shirt, torso, t-shirt, and shirt.
Did you miss this above? “In just two years (95/96), 41 of the 121 people hit by NYPD bullets were hit by NYPD bullets that went through somebody else first. 36 were hit by FMJ, 5 by JHPs. 23 of those were bystanders and other cops (22 FMJ, 1 JHP). 18 were suspects (14 FMJ, 4 JHPs). Source is a NYT article about the1997 SOP9 report.” No details on how many exited a torso and how many limbs. Completely discounting the possibility is the same kind of mistake as taking it too far. Don’t get carried away in either direction.
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The ones I tested are the “Low Recoil” ones. Those are the ones sold to the general public for personal defense.
The “tactical” are sold to law enforcement only. The ballistics reported by the company look to be identical; the only difference may be in the box quantity (personal defense = 20 per box, law enforcement = 50 per box).
I don’t think there’s any difference between the ammo offerings at all, other than price-per-round and quantity.
You may also want to consider the newest ammo I’ve tested, the Lehigh Extreme Penetrator — it is my new favorite recommended ammo for .380 pocket pistols.
GREAT SERIES: I own 9mm; .45acp . I carry a kahr 9for cow; been getting hooked on trying out the .380. IMHO as a civilian only trying to “break contact” ; it provides “enough”of what I’m looking for. with the benefit of reduced over penetration; recoil; muzzle blast; weight.
7.65 browning worked for decades as a military and LEO cartridge in Europe. In the typical “bigger is obviously better” u.s; we took the .38spcl and souped it up to the .357; .44 special up to the .44 magnum; and 45 long colt up to the 454. casual magnum. Which certainly have their place the game fields. but why discount another stroke john brownings genius with decades of successful use behind it? A reasonably powerful bullet stopping (dumping of its energy) in the intended target is just about perfect.
GREAT SERIES: I own 9mm; .45acp . I carry a kahr 9for CCW; been getting hooked on trying out the .380. IMHO as a civilian only trying to “break contact” ; it provides “enough”of what I’m looking for. with the benefit of reduced over penetration; recoil; muzzle blast; weight.
7.65 browning worked for decades as a military and LEO cartridge in Europe. In the typical “bigger is obviously better” u.s; we took the .38spcl and souped it up to the .357; .44 special up to the .44 magnum; and 45 long colt up to the 454. casual magnum. Which certainly have their place the game fields. but why discount another stroke john brownings genius with decades of successful use behind it? A reasonably powerful bullet stopping (dumping of its energy) in the intended target is just about perfect.
Whatever type of bullet you use, make sure it fully penetrates your target. The facts are very clear, blood lose is the only reliable way to stop a human, and two holes bleed out faster than one. I don’t use a hollow point in anything with less energy than a .357. 9mm, 40, 45s all should be hard cast or FMJ. Hollowpoints lead to dangerous underpentration if they work as advertised. Luckily many fail to expand and work like the more effective FMJ and your only loss is the extra money wasted on hype and magic bullets and the straw man “overpenetration”
I disagree, I think FMJ are a effective self defense round , for one thing they cost less the other is that in the world wars WW1 and WW2 FMJ bullets in 9mm and 45 ACP killed soldiers as well as wound soldiers. If you get hit with a FMJ bullet you will drop to your knees or die. That bullet will travel trough your body causing damage internally and exit wound , if a person does not die instantly they will bleed to death in short time. People are not paper targets if you get hit with any bullet you will know it. Just knowing you are hit will cause psychological trauma as well as physical trauma. Hollow points expand on impact but on thick clothing or bullet proof vest are less effective. The other problem is that hollow points are more prone to jamming in semi autos, especially the 45 ACP, The 1911 was not designed for hollow points nor any military firearm . Hollow points are more a marketing ploy than anything else , since they cost more they try to push the ammo in sales while their effect is no better than FMJ. Remember if a person gets shot they will know it and feel it no matter if hollow point or FMJ . I use FMJ in my 45 ACP for home defense without question, I know if a intruder gets hit he or she will go down . I see what the bullets can do on plinking on milk jugs and other items and believe me no one would want to get hit with a FMJ bullet 9mm or 45ACP . You can use your hollow points but I will stick with my FMJ , if it was good in WW2 than it is good for me too.
I have yet to see a single perp walking around made of ballistics gel. The second you find that guy, he will make everything you noted in your story valid, until then it’s just more, “not completely accurate”, info. There are several Youtube videos of surgeons and other medical professionals that have extensive experience with GSW, and from what I have seen, they would generally disagree with your synopsis regarding over-penetration. Source below.
Exactly, anyone ever see a .45 acp hardnose, tumble wound?
This round often tumbles & does excellent damage.
Ever seen some of these bad guys? How hugely massive in body size? Not everyone is as described. The odds of a pass thru, overpentrating round, hurting, killing someone else are very, very remote..bad guys often seek targets in isolated/desolate places. (Not many good folks around).
The .357 magnum & .45 acp just flat out get it done. That’s my choices. The .40 as of the last decade does too..
First thing first, Stop the threat, plain & simple.
When possible use a 12 gauge or rifle.
Stay safe.
My 1911 has no problems with feeding or ejecting hollowpoint rounds. I do carry 230 gr PDX1 Winchester hollowpoints,but I would’nt have a problem using FMJ’s, if thats all I had .