Food for thought about Over-penetration.

[jimbo]

I am convinced that the most critical factor to stopping an assailant (after shot placement) is sufficient penetration. Yet a majority of those posting on all firearms sites I frequent express huge concerns about the liability and danger from over-penetation.

Hence, my question...

How fast exactly is a .45 round traveling after being launched from the barrel of a gun at 850 fps, after passing through the meat, bone and organs of your attacker, after passing through 2 sheet-rock walls, and after exiting the paneled siding of your home?

Is it still traveling at 350 fps? 250 fps? 100 fps?

Are concerns about over-penetration over-emphasized?

Isn't a rapidly expanding hollow-point round that misses an assailant a far greater overpenetration threat than a round that guarantees an exit wound that hits an assailant and then travels at 150 fps afterward?

Just food for thought as I wonder if there isn't too much thought given to overpenetration and perhaps not enough thought given to insuring the bullet hits deeply into vital organs after passing through an arm bone or a heavy leather jacket.

Sorry for wandering, but has anyone ever studied or estimated the velocity of a 230 grain bullet that has passed through 18 to 20 inches of meat and gone through 2 walls?

How about the velocity if a 230 grain FMJ that has only passed through 2 walls? How fast is it moving?

 

[EJ]

YMMV

Depends on where you are--

I have a home office in a suburban area near a forest preserve and also used to live on a farm-- Couldn't care less about overpenetration--

I also am in the city half the time-- Condo--
If I used the HD gun and there was ANY residual velocity-- with my luck it would hit a baby in a cradle--etc etc--
In the city I use a 38Spec with Glasers--

 

[sanchezero]

Isn't a rapidly expanding hollow-point round that misses an assailant a far greater overpenetration threat than a round that guarantees an exit wound that hits an assailant and then travels at 150 fps afterward?

The FMJ that misses will probably be going just about as fast as the JHP that misses.

 

[agtman]

Overpenetration ...


... is overblown.

In LE it's a nonissue, statistically. I suspect the same is true of justified civilian defensive shootings.

In terms of percentages, a far greater worry for the safety of innocent bystanders (IBs) are the rounds fired by LEOs that MISSED the BG, and then careened on by or ricocheted toward, or into, God-knows-who. Unfortunately, this is another unsatisfactory byproduct of LE training that emphasizes "more rounds on target faster" - which typically involves a hicap 9mm - over the need to make every shot count (because you have fewer of them) with a caliber fully up to the task of instant incapacitation, or something like it.

Part of the problem lies in minimum-standard recruiting. This is followed closely by half-assed firearms qualification requirements, such as once-a-year 50-round shoots on pathetically easy courses of fire, which my 95-yr-old Grandmother could do blindfolded. More frequent and intense firearms training would help, but when budget-anal police administrators start swinging their fiscal ax, the money that might fund such training goes bye-bye.

If there's any good news, it's that, statistically, even the IBs hit by LE rounds that MISSED the BG still constitute a fairly small percentage within the total universe of LE shootouts with BGs. Even smaller still is the number of IBs who were struck by a round that HIT the BG and then "overpenetrated." The word "minuscule" comes to mind.

In short, the time spent worrying about whether your chosen defensive load might "overpenetrate" its way into an IB is better spent at the range, where you'll practice (1) accurate shot-placement into an armed attacker's vital areas and (2) some basic tactics, such as moving to available cover and reloading your pistol under stress.

 

[tiberius]

In regards to pistol ammunution, I believe that concern for over-penetration is generally unfounded. Penetration is required to reliably stop a bad guy. Any cartridge that is designed to never over-penetrate, will at times not penetrate deep enough. Since it is IMPOSSIBLE to have a bullet that penetrates the exact, appropriate depth every time, you are much better off with a round that WILL penetrate enough, even though it runs the risk of over-penetration.

Remember, you will only be shooting when you have NO other choice so it is most important to stop the threat as quickly as possible. This will be safest for everyone, including the bystanders.

This is not to say that you should use a .375 H&H in your mid-town apartment, however .45 ACP hardball is enough.

 

[Tropical Z]

There are valid points to both sides,but the recent thread where the majority picked a CZ-52 sending FMJ's at 1600+ FPS out of the barrel was nuts and extra dangerous if you miss.
In my P32 ALL i use is FMJ's.

 

[Mannlicher]

for my money, "over penetration" is about as valid a consideration as " for god's sake, don' t use hand loads in your ccw weappon because a jury will crucify you"

Buzz words of the new gun owner, fed a daily diet of gun mag articles, and BBS myth and legend.

If you hit your target, there won't be any "over penetration". If you miss, well, then just about anything will go through a wall. Thats what practice, and 'gun control' are all about; hitting your target.

 

[Crimper-D]

Big Heavy and Slow DON"T overpenetrate

45ACP Ball penetrate, expend all their energy in the target and stay where they stop. One of my more intresting jobs was as a Coroner's Investigator. I've helped dig those big bullets out of several dead people. The main reason I have a .45ACP on my carry permit = they WORK! Oh My do they work!
The most memorable example = A "deadx7" little criminal who attempted to hold up a gunstore with a sawedoff singleshot rifle He missed his shot at the armed clerk, who then expended the entire contents of his 1911 into the fool at pointblank range. We figured the first round between the eyes did the job, the remainder of the magazine may have been over reaction on the clerk's part although he wasn't charged = Justifiable Homacide, but there certainly was NO overpenetration,
all bullets were still in the remains - verified by X-ray.
Goriest post I ever scrubbed in on - took 2 days to verify the path of each of those slugs, any one of which would have been a fatal hit. The ME's comment on the whole thing = "A bit of OVERKILL here, but nice grouping!"

 

[Amish]

I don't believe in over penetration with handgun rounds. No such thing if the bullet hits the body and is a hollowpoint.

 

[22luvr]

caliber size and locale are factors....

One of the cardinal rules in handgun safety is knowing what is behind your intended target. If you're out and about, an assailant is probably not going to attempt to rob you or hurt you in, especially with witnesses in the area. Statistics and probabilities of witnesses being behind your intended target are going to be very slight at best, day or night.

In the case of being in an enclosed area such as an apartment or home, then, in some circumstances, there is the danger of penetrating a wall and striking someone.

In smaller calibers (.22, .25, .32) I use FMJ's and don't worry too much about over-penetration; In the larger calibers (.38 spcl, .357 mag, 9mm, .40 S&W) I use JHP's only because of the increased velocity and projectile weight.

 

[agtman]

"I am convinced that the most critical factor to stopping an assailant (after shot placement) is sufficient penetration."


Yep. And in the case of HP bullets, you want penetration first, then expansion.

The importance of penetration to achieving instant incapacitation (i.e., "stopping power" - or something like it), and the seemingly popular bugaboo of "overpenetration," are well-analysed here:

http://www.firearmstactical.com/hwfe.htm

Especially good are the paragraphs found in the Section entitled, "Ammunition Selection Criteria."

HTH.

 

[amprecon]

I'm a little taken by Crimper-D's statement about all bullets remaining in the subject. For all the bullets to remain in the subject at such apparently close range is slightly unnerving. Those bullets should've gone through him, unless he was heavily clothed, but I would imagine the head shot would've been a thru & thru. It would be interesting to know what kind of bullets were used.

 

[444]

I am no expert, but I have seen quite a few people that have been shot with handguns. I didn't have the time to make a study of their wounds, but I can tell you that from my experience, very few of these patients have exit wounds. I am trying to think of one. This includes suicides where a handgun is fired into the target from muzzle contact distance.

 

[George Hill]

A NON ISSUE?

I call BS on that.

Overpenetration is just as Liable as a flat out miss.

ANY bullet you launch - it's your butt in the sling if it hits someone other than your attacher. I don't care if goes through the badguys left eye first... if hits someone else your arse is natural astro turf.

That makes it an issue. A critical issue. Don't give a fig about statistics. Stats say an average guy will not get shot even once in a lifetime and will never have a high speed blow out. I've caught 3 and had 2 high speed blowouts in the last 15 years. Just because it isnt likely, doesn't mean it aint going to happen. These things CAN and DO happen.

You can savor your cavalier attitude now - but if it happens - you will be more sorry than you have ever been in your life.

 

[444]

Ok, George, let's hear you experiences with handgun overpenetration ? Don't just "call BS", back it up.

 

[George Hill]

 

[444]

That's what I thought.

My turn to call BS (what a Utah expression).

 

[Gabby Hayes]

If you don't think overpenetration is an issue, you might want to reconsider. Not to steal his thunder, but BrokenArrow has posted this story from the NY Times (March, 1997) on several occasions:

"In New York City during the last two years, seven of the bystanders shot by the police were struck by bullets that passed through other people.

The report released Thursday covers shootings from 1995 and 1996. Of the six innocent bystanders struck by hollow-point bullets fired by police officers in the Transit Bureau, one was hit by a bullet that ricocheted and another by a bullet that passed through an object. Of 15 bystanders shot by conventional, full-metal-jacket bullets, five were hit by bullets that had passed through another person and two by bullets that had gone through an object.

Forty-four police officers accidentally shot themselves or were accidentally shot by other officers over the same two years, according to the report. Of the 40 officers shot by full-metal-jacket bullets, two were hit by ricochets, 17 were hit by bullets that passed through other people and two were struck by bullets that passed through objects. Of the four police officers shot by hollow-points, one was hit by a bullet that passed through another person.

Fifty-six suspects were shot and killed by police officers over the last two years. Forty-one of them were killed by full-metal-jacket bullets, 14 of which passed through other people first and one of which first passed through an object. Fifteen others were killed by hollow-point bullets, four of which passed through other people first."

 

[444]

Gee, I couldn't even get George to take the bait after playing the Utah card.
Very cool customer.

That is an interesting article about NYC. I think I had seen that before. I wonder how many shootings there are in NYC and what kind of percentage that comes out to ?

 

[jimbo]

I realize full well that overpenetration can and does happen. What I am trying to determine, and I can't find this even guessed at anywhere, is HOW FAST is a bullet moving after it passing through a person's body. Is it 100 FPS? 10 FPS?

How deep did the bullets penetrate into the officers and bystanders who were hit by bullets that had already passed through other people? I mean, did they receive life-threatening wounds or did the bullet even fail to break the skin of the 2nd person hit by the bullet?

I am trying to quantity if overpenetration is indeed a problem or not, if the velocity of a spent bullet after passing through someone is less than 100 FPS?

 

[BrokenPaw]

I call BS on that. Overpenetration is just as Liable as a flat out miss.

George, I think the point that people are making with regards to the dangers of overpenetration from handgun rounds is that: (1) yes, you're still responsible if the round you fired penetrates the Bad Guy, but (2) after going through clothing, Bad Guy, more clothing, and (potentially) drywall et al, a bullet that "overpenetrates" will have shed so much of its kinetic energy that it'll be unlikely to cause horrible injury in the event that it hits an innocent bystander.

Now, rifle rounds are a different story. A 7mm Rem Mag round that's moving at 2500+ fps when it hits a Bad Guy probably would retain enough KE to ruin someone's day after it came out the other side.

-BP

 

[buzz_knox]

In LE it's a nonissue, statistically. I suspect the same is true of justified civilian defensive shootings.

Wrong. NYPD went to hollowpoints not to increase stopping power, but to reduce their liability for overpenetration injuries. They were getting sued several times a year for exactly that issue, resulting in rather hefty settlements each year.

As for how slow rounds don't injure, the Army Wound Ballistics Laboratory determined that the threshold energy level for a wound is 58 ft lbs. Do the math yourself and you'll find that most any round can easily carry that much energy after exiting a body.

 

[ElAlumno]

According to the FBI Ammo Tests the .45 ACP 230gr. FMJ will penetrate about 33 inches of ballistic gelatin under the "HEavy Clothing" protocol. If you figure a 12" to 18" pentration on the initial taget, you still get over 15 inches of penetration.


Figure it this way. Initial penetration 15" of gellatin. That round exists still having enough energy/velocity to penetrate close to another 15" of gelatin.

IMO anyone that dismissess penetration, on either end of the spectrum is being foolish.

 

[George Hill]

Can't a guy unplug and go out? After I last posted here, I took my wife out. We had a great time... We went to the store to stock up for the week and for me to find new and interesting reasons to hate this town I am now living in. Didn't plug back in until this morning.

I was going to mention the New York shootings... but someone already beat me to it.

The issue is an obvious one. Over-Penetration is an issue. If you can't see that - then it can't be explained to you.

 

[Mute]

Keep in mind also that a penetrative round doesn't always go straight in and straight out. It could exit on a completely different path from the entryway. IOW, being sure of the background may still not prevent hitting an unintended target with an overpenetration.