The Myth of "Over Penetration"
 

No, you perverts, not that kind - we're talking firearms here. I started out posting this as a reply on another thread, but it started to take on a life of its own, so I figured I would give it a life or its own. Anyway...

"Over penetration" has got to be the most over used term of all time in the defensive handgunning world. I would be surprised to learn of a documented case where a handgun bullet went through the bad guy and went on to injure anyone else in a self defense shooting. I believe the chances of this actually happening are effectively zero.

In sharp contrast, there are far too many documented cases of failures to penetrate sufficiently to stop the fight. Too many good guys have lost their lives over this one. Over no more than marketing hype and disinformation.

"Over penetration" is no more than a bull shyte myth perpetrated by the ammo manufacturers and their cheerleaders in the gun press. It's marketing, pure and simple, directed at the less than savvy ammo buying public. They understand most folks will never shoot anything more threatening than a piece of target paper or a pop can, so they will never get to (or have to) see for themselves just how well their chosen brand of designer ammo performs on live targets.

Bottom line is, there is no such thing as too much penetration. The idea that a bullet design can somehow be matched to its intended cartridge to provide just the right amount of penetration, not too much now (but at the same time not too little), and somehow be made to stop when it reaches the vitals (but not before) is laughable. There are simply far too many variables. Size and weight of your adversary, what they are wearing, what angle you hit them from, and more all conspire to make it impossible to predict just how much penetration is "enough" vs. how much is "too much".

Add to that the fact that any particular designer hollowpoint is more than likely loaded in a number of cartridges that share the same bullet diameter and launch them at widely varying velocities (.38 Special and .357 Magnum, for example). How can the same bullet possibly perform to the same level of "ideal" penetration when one cartridge starts it at 800 fps, and the other starts it at 1,300 fps? They simply cannot.

In light of all of this, it is never a mistake to load up with ammo that provides maximum penetration for the caliber in question. This usually means the heaviest bullet the caliber will handle. It never means hollow points, no matter how pretty the mushroomed bullet in that ad may look, or how nasty the "wound channel" looks in ballistic gelatin. Neither represents real world bullet performance. It's all directed at the vast market comprised of shooters that will never never gain any first hand experience, nor be likely to meet anyone who has.

Like I've mentioned in other threads, I have never shot a human being and hope to God I never will. I have, however, long since lost track of how many game and non-game animals I've shot. Most with rifles, of course, but dozens and dozens with hand guns as well. A good number of those animals are about our size, some smaller, some much bigger. I've tried hollow points of various pedigrees, every one of which was touted as the "latest and greatest" of the time. Damn near every one of them failed to penetrate sufficiently to put the animal down quickly. Even .357 and .44 mags loaded to the gills, even on critters as small as coyotes. At least these kinds of animals run off when hit (some of them for miles...), so I was never put in danger by any of those failures. But, I'm here to tell you - I have seen some pretty heavily loaded hollowpoints from magnum revolvers simply go "splat" on the sides of mule deer, coyotes, pronghorns, and such, providing no more than an inch or two of "penetration".

In sharp contrast, the ones I hit with non-expanding bullets (typically my own hard cast semi wadcutters) at even moderate velocities go down very quickly. They go down quickly because the bullet goes all the way through, therefor reaching the vitals every time. That is what kills, and more importantly, incapacitates quickly. In my personal experience, a moderately loaded 250 grain hard cast semi wadcutter at, say, good stiff .44 Special or .45 Colt velocities (under 1,000 fps), kills far, far more effectively than a lighter hollowpoint going 500-600 fps faster. I've seen it myself on too many occasions.

Granted, my hunting experiences encompass revolvers only, as there really are no auto loaders that I feel make suitable hunting handguns. But the same principles apply. Probably more so, with the average auto loader giving up so much in terms of case capacity, and therefor bullet weight and velocity, to revolvers with similar bore sizes. With these "capacity challenged" chamberings, the auto loader becomes even more critical with regards to achieving enough penetration to be reliably effective. In these guns, nothing beats the heavy, truncated cone, flat point FMJ. The round noses are a distant second behind them, but the designer hollowpoints aren't even in the race. I won't even consider the damn things.

Wait, you are not or are talking to the perverts???

Ok, so what's with those ballistic gelatin slabs that show a garden variety JHP penetrating 10-12" with heavy clothing in front of it? I also have never heard of an overpenetration issue in a defensive shoot. But I know my own center mass less than 12" thick and I'm kind of big and usually not wearing anything thicker than a t-shirt. Aren't those ballistic gelatin slabs made to simulate human tissue in thickness and resistance?

Interesting post. Surely something to think about.

Something that I've always wondered about, if the gelatin is supposed to simulate flesh, is that a gut shot, or is that counting stuff like ribs, sternum, etc...?

Ballistic gelatin tests only do one thing - they demonstrate how ell bullets penetrate and expand in ballistic gelatin. That stuff in no represents a living, breathing person's tissue. A great deal of effort has been put forth to somehow correlate how a bullet behaves in that stuff to how it behaves in real living tissue, but has been so far unsuccessful. The stuff is too consistent, too homogenous. It has no fiber, has no bone, has no variation in density, and no variation in fluid content as flesh and organs do.

Advertising types love it, though, because of how nicely hollowpoints are formed into pretty mushrooms in it, and how "shocking" the initial wound channel looks in it. It makes the temporary wound channel look permanent and quite impressive, so the ad guys love to tout the "shocking" qualities of their particular hollowpoints. Problem is, one we get above about the size of a ground hog (rock chucks out here) and below the velocity of a .220 Swift or .22-250, "shock" becomes a myth as well. It just doesn't happen.

Death is caused by the permanent wound channel. Incapacitation is not caused by "shock" in anything near the size of humans. Incapacitation is most effectively caused by hitting the central nervous system, with causing rapid blood loss in second place. Entry wounds generally don't bleed anywhere near as much as exit wounds, and hitting anything important in either the central nervous or circulatory systems requires penetration. Not expansion.

This seems on-topic...

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not that I would recommend it...

http://forums.pelicanparts.com/uploa...1299387222.jpg

Hydraulic Shock
 

weatherby with a .257?


http://forums.pelicanparts.com/uploa...1299389582.jpg

The 12" of penetration comes from needing to go in the arm, and into the chest.

It came from the Miami shootout if I've been told right.

Show off.

Shoot for the heart, Ramone.

Jeff, I know you're going the right direction with this. There is another thing to consider beyond regular penetration. Exit through skin. Skin is tough. The bullet has already been reduced in speed by going through flesh. Exiting the skin means it is really slow. Hand gun ballistics are very different than rifle. The velocities are 1/2 to 1/3rd.

This is why I load my .380 with FMJ and my .45 with alternating Corbon and FMJ. If I had access to commercial semi-wad cutters, I would use those.

230gr.fmj in my 45acp is my standard "friend"

my concern is more for the shots that miss

trust and believe that cavitation matters, probably not as much as the size of the hole, but it does bad things to tissue

10mm over penetrates my wallet.

Jeff,
The other "myth" that drive me crazy is the "big gun = big recoil" myth! Heck, my little 15 year old daughter fired my Remington Rand M1911A1 .45ACP last weekend at the range with no problems at all. The gun is heavy, so I helped her support the gun, but she handled the mild recoil just fine. If you compare the recoil of a full frame gun to a mini, like my wife's Ruger LCP at 9.3oz, the Ruger has an uncomfortable recoil!

Art,
You aren't kidding about recoil with the LCP. I usually only run two or three mags through it at the range to stay proficient. The +1 magazine extension helps a little.

This works for me as well! :D

Jeff, interesting insight on the ballistics gel being more/mostly a marketing tool.

Your point about it being too homogenous to be a good representation for the human body makes perfect sense.

Do the firearms/ammo designers (not the marketeers) use the same (b. gel) while carrying out the design process or do they use something more representative of the human body, for example pig to get a better handle on the many variables?

Originally Posted by Rick V
230gr.fmj in my 45acp is my standard "friend"

This works for me as well!

700 rounds spent yesterday 'tween my Dad son & I

plus some M2 ball, 12ga, .22 & 7.62x51

This is what I DO know about a 45 cal FMJ
A BIG pig shot between the eyes ..The bullet will travel all the way dwm into the shoulder area being stopped by the BIG bones there
A typical farm sheep Between eyes will travel through the scull and about 4 inches dwn the spinal column (their head is ALL bone)
SO...to shoot a human...I am sure wherever it strikes it will come out the other side

The vast majority use ballistic gelatin. It's convenient, clean, and relatively cheap. They used to justify its use by including a "control" sample of a bullet known to have certain performance characteristics in real flesh and blood. Then they noticed any correlation between how a new designed compared to the "control" in gelatin did not necessarily carry that same correlation through to how it performed in real, living creatures. In other words, even if a given design "outperformed" the control in gelatin (and we must be careful to note how the manufacturer quantified that - more penetration? - more expansion? - it seemed to always depend upon which their new bullet did better), it may very well underperform that control bullet in real flesh.

Some labs did use pigs and/or goats for a time. If memory serves, the FBI did this some years ago. Again, if I remember correctly, there was some hue and cry over these tests as being "inhumane". Not sure if those were the FBI tests or someone else's. At any rate, they then went to shooting already dead pigs or goats, ones that had been "humanely" euthanized. Guess what? The testing lab discovered there was a substantial difference in how bullets behaved in live vs. already dead animals. To the point where shooting dead ones was deemed too inconclusive to be worthwhile.

What they also discovered were significant differences in how the same bullet, fired at the same velocity, impacting the same location on the animal, behaved differently from time to time. Most of the time they would work as desired, but sometimes they would get some very surprising results, ranging from the infamous "splat" accompanied by almost no penetration, to full penetration with no expansion to speak of. These hollowpoints were simply all over the map, and disturbingly unpredictable.

The FMJ's and hard cast bullets never displayed this unpredictability. They simply drive through with no expansion, pretty much every time. The roundnoses sometimes change direction when glancing off bone or something, but the flat nosed truncated cone or semi wadcutters go straight pretty reliably.


Yes, exiting through the far side skin will challenge even the most powerful handgun round. Even powerful hunting rifles can have a hard time with this one. The skin is very elastic; far more so than most would believe. I've read accounts of very slow motion photography recording skin stretching a couple of feet to catch a bullet trying to exit, although I have never been able to find such footage.

The key to overcoming this tendency in a handgun is to have a bullet with sharp cutting edges. Keith figured this one out back in the '20's, and started designing his no famous semi-wadcutters. They are now known interchangeably as "semi-wadcutters" or "Keith style" bullets. They have a flat point (kind of an oxymoron, huh?) and a second sharp shoulder meant to cut their way through tissue. And boy, do they work. I have never recovered one from a game animal. They always cut through the off-side hide. The most astounding penetration I ever achieved with one was full length, brisket to butthole, on a mature bull caribou. This was from the .44 mag. That's damn near six feet of penetration, plus an exit wound. All from a moderately loaded .44 mag.

http://forums.pelicanparts.com/uploa...1299456032.jpg

By the way, I've hunted the same critters with stuff like the .375 H&H magnum, loaded with 300 grain bullets at just over 2,500 fps. I hit one in the brisket, facing me, in much the same way as the one with the handgun. It went 3/4 of the way through, failing to exit. I've taken a good number with the handgun, and a good number with the rifle. The handgun, with proper bullets, exits every time. The rifle does not, even a big thumper like the .375. Solid bullets in the rifle would change all of that, but, alas, they are, for the most part, illegal to hunt with in the states.

http://forums.pelicanparts.com/uploa...1299456385.jpg

Are humans easier or harder to kill than animals (mammals) of similar size/weight?

Kind of gruesome question, but goes with the topic I'd think.

Humans are supposedly more "high strung", or give up more easily to heavy trauma. While I have no way to prove this, I believe it's an individual thing. Some guys, when hurt, fight harder. Some give up. Same with animals. Generally speaking, though, I would guess humans are, pound for pound, easier to put down than animals. From the front, anyway, where most defensive shootings are going to take place, our vitals are not nearly as well guarded as an animal's from its side. The animal's shoulder can be in the way unless it is perfectly broadside, where ours won't. Plus, our skin tends to be thinner, and our ribs lighter than animals of the same size. That, and most of us don't have much fur...

Except the furry Irish kind of human, of course.

I wonder if our brains get in the way. A human can realize, or think that, he is mortally wounded. I'm not sure an animal does?

Over penetration is not a myth. Massad Ayoob has documented cases in his writings.

Massad Ayoob makes a living as an "expert witness" touting his own pet theories. He writes a lot of books. He has become the erstwhile prophet of "over penetration". He is simply beating his own drum, trying to sell more books and book his next gig on the witness stand. Not many serious students of defensive shooting can mention, or hear his name without either rolling their eyes or snickering. He is the only one who believes his hype, and make no mistake, he has a significant financial interest in perpeptuating it. It is, simply put, a statistical non-issue.

The real issue, as borne out by real world shooting cases, is failure to stop the fight due to under penetration. There have been countless documented cases of this. In a defensive situation, when things get that serious, penetration consitently wins the day. That simple fact has been demonstrated time and again in real world shootings.

Ayoob has also become infamous for his stance on handloads for self defense. His claim is that a jury can be made to believe that a man who defended his life was some kind of mad scientist creep, concocting "more deadly" ammo in his dark basement, and secretly waiting for the day he could use it on someone. His "expert advice" is to absolutely, under no circumstances, use handloads in a defensive pistol to avoid any such impressions. He is full of shyte on this one, too. There has never been a case of a justifiable defensive shooting that turned on defensive shooter because he or she used handloads. As a matter of fact, the type of ammo used simply does not come up.

Careful there. You may know about the Harold Fish case in AZ. He did seven years in the joint before AZ changed the law and sprung him. Fish very justifiably shot a madman coming at him in the woods while hiking. The fact that Fish used a 1911 in 10mm was a large part of the prosecution's case, claiming it was an ueberpowerful round that only gun nuts would ever use. Fish even tried to render first aid to the dying man, hiked a few miles to get a cell signal to call it in and (foolishly) first fired warning shots at the crazy guy's dogs that were coming at him. Obviously, he had a bad lawyer and was unlucky enough to draw a very gun-ignorant jury. But his case is often cited in AZ as a reason to carry whatever caliber gun and ammo brand your local cops carry.

Also, my dad used to hand load when I was kid. I don't remember any of it ever misfiring. For decades his home defense ammo was a batch of .45ACP JHP's he made himself. I bought him a box of HydraShoks and told him I'd shoot off that old homemade ammo. And wouldn't you know it, the first round went "click." I recocked the hammer, fired and "click." One other round in the batch was also bad. I've never had that happen with Federal HydraShok or Speer Gold Dots.

There will always be abberations and abuses by overzealous prosecutors. The unpredictability of the American courtroom has become rather infamous. I, for one, will hedge my bets towards stopping the fight rather than trying to predict what will happen in court. After all, failing in the former may not even require one participate in the latter.

I also feel it fair to point out that these were not handloads. Remember whn the first Winchester Black Talons achieved some sort of mythical status as some magical "uber-killer"? We were advised (by guys like Ayoob) to never use them, because juries frowned upon their use, and prosecutors would have something else to go after us with?

I have loaded literally hundreds of thousands of rounds of ammunition in my lifetime. I have never had a round fail to fire for any reason. There is some care and attention required - not everyone is up to it.

When Oregonian Ross Seyfreid won his IPSC world championship in South Africa back in the early '80's, he won when his closest rival's gun failed to fire. The round up the pipe had no powder in it, and the primer propelled the bullet just far enough to become lodged in the barrel, effectively disabling the gun. He couldn't even clear it and recover. It was a factory load. Mr. Seyfreid used his own handloads.

It's been a long time since I did any reloading, but I don't think I ever had any misfire. But then the ones I got from my dad were probably 30 yrs. old and improperly stored.

Fortunately, they've changed the law in AZ since the Fish case so that the burden of proof is on the prosecution to show the shoot was not justifiable. It used to not be that way. The problem is that a lot of these wacky cases become case law.

Fortunately, I think the tide is turning (or has turned already) in the whole area of right to carry / right to defend. There have certainly been anti-gun prosecutors that have taken their politics to court with them in the past. I think we are seeing those types getting beaten back in the face of recent court rulings.

I hate to keep beating on the guy, but Mayoob (and certainly others) sure "made hay while the sun shone" on these self-defense issues. They had the entire shooting world running scared of using the "wrong" caliber with the "wrong" bullet or, God forbid, with handloads. Citing obscure examples of one or two cases where someone got into trouble because of their choice in a defensive arm and its ammunition, all the while completely ignoring the volume of failures reported due to insufficient penetration, or the number of folks never even prosecuted for using what they would deem to be the "wrong" equipment, and other information contrary to their positions. These people succeeded in making names for themselves as "experts", but they were only considered "experts" because of the number of court cases in which they had testified. Sort of like Zsa Zsa Gabor - she was famous for, well, for being famous...

I find this thread very interesting. You submit a compelling argument.

So, if I understand correctly, you are saying that something like a WWB round is a better SD round than a Speer Gold Dot. Is that correct?

I have a 9mm (not interested in the 9 vs 40 vs 45 discussion right now). I know that the popular bullets whether JHP or FMJ are 115gr, 124gr and 147gr (with a few other oddballs like 90gr, 135gr and 158gr). There is always lots of talk of SD rounds and using the various weights and the various issues (147gr may not expand and may overpenetrate, 115 is too light and underpenetrates [or packs a wallop], etc....). From the sound of things, you would recommend a big heavy bullet, preferably a SWC or if not available a FMJ.

So, based on the 9mm, is the recommended bullet an FMJ 147gr (or 158gr)?

Thanks

Yep, heavier the better.

While a 147 gr Truncated Cone Full Jacketed is perfection in a 9mm for defense or hunting, it is very difficult to get. Hornandy makes them in 123 gr and should be easy to find online.

I have had .356" annealed Marine Bronze 147 gr. turned up just for defense use. Loaded to +P+ pressure levels it can penetrate Elk shoulder to shoulder from 15 ft. That is through upper leg bone, ribs on both sides, and the upper leg bone on the off side. These work superbly in my Glock.

Hmmm Truncated cone, FMJ. That sounds a lot like a .357sig round...

Sooo, truncated cone is better that normal FMJ?

Always?

Does barrell lenth make a difference? With a short barrel, typical of the "mouse guns" designed for pocket carry, there is a big difference in velocity with lighter bullets vs. heavy bullets.

With a barrel at 3" or less, would penetration be better with the lighter, faster bullet?

Or is heavier always better?

Very informative thread......

Assuming similar construction, yes, heavier seems to always penetrate better, regardless of the lower velocities attained.

The truncated cone profile induces more trauma. It's flat nose cuts a more damaging permanent wound channel than a similar weight round nose. The rounds nose "parts" tissue in front of it, allowing it to fold back in and close the wound, reducing bleeding. The round nose does not remove any tissue. The truncated cone, or semi wadcutter, actually cuts and removes tissue, reducing the tendency for it to simply fold back into place after the bullet passes. The victim keeps bleeding, profusely. That's the idea.

Decidedly yes. The flat tip full metal jacket semi auto bullet (like the Hornandy Truncated Cone 123 gr. bullet), does not expand and is not deflected as easily as a round nose full metal jacket projectile does.

The goal should be to duplicate as much as possible the Keith type hard cast bullet that has been used on everything up to and including elephant successfully. It features a "truncated cone" profile as well as a very hard lead alloy. Most expand very little in actual shooting real animals testing. But the penetration is superb with the straightest internal path.

Penetration and less internal deflection allows for better bullet placement. It gives you the ability to place a bullet in the vitals from almost any angle of engagement. Not all targets are facing you or broadside all the time.

Of course, there is a correlation between penetration and velocity, so do not expect miracles with low pressure pistol rounds. You do have to load these up.