[RyanM]

Well, the best way I explain things is through analogy, so here's an analogy.

You are going to be involved in a car wreck today. You don't get to choose the time, place, or circumstances. Maybe you'll back into your mailbox, or maybe it'll be a 65mph + 65 mph head-on collision on the highway. It's completely inevitable, and you'll be knocked out, strapped in the car, and rolled down a hill if you try to resist. All you can do is choose between two cars.

You can either get into a car that was crash-tested at 120 mph against an immovable solid steel wall, and passed that test, or you can use a car which did fine in the test where it was crashed into a small tree at 25 mph, but failed miserably at the 120 mph steel wall test. Oh, and the first one is a brand you hate, while the second is your favorite.

"But, but," you might say. "The first test is too hard. My favorite brand of car couldn't possibly pass that one. Couldn't you just make the second test the industry standard, since low speed impacts against yielding objects occur more frequently? Or maybe compromise and test against a big tree at 55 mph? No one crashes into big steel walls at 120 mph!"

Well, it's your choice. You're going to crash into something today. You do not get to choose what it is or how fast you're going at the time. Which car do you use? The one that passed the "unrealistic" test, or the one that only passed the "realistic" one?

Same with 4-layer denim. No, people do not commonly wear 4 layers of denim. But a bullet that's overengineered to pass that test is also very likely to perform against real world obstacles of lesser magnitude. Overengineered beats barely adequate every time, especially when it's your life on the line.

[Deer Hunter]

People don't wear denim over their heads. :)

[Jonathan]

I think you phrased this question extremely well, but perhaps it suffers from the same flaw with bullet testing decisions.

Consider this:
A car which is engineered to protect the passenger compartment in a 120mph crash (but only this test) will have a crumple design that is extremely rigid. This design will probably behave like a 1950s pickup in a lower-speed collision, transmitting too much shock to the passengers.

In contrast, the 25mph car will have softer crumple characteristics, making it much safer at 25mph, but deadly when crashed faster.

I don't think there is a clearcut answer for which one is better. I'm sure auto engineers have carefully considered this situation, and the result is that cars in real life aren't prepared for 120mph wrecks. The requirements for such an event would result in detrimental performance in wrecks that are much more likely to happen. In real life the designs are based upon what will be the most likely threats.

[RyanM]

Well, in this case it's also implied that the 120 mph car did just as well as the other car in the 25 mph test too.

With bullets, that's how it is, anyway. I've yet to see a bullet that will expand when fired through 4 layers of denim, but won't when fired into bare gel. Although there are some that overexpand against bare gel but do okay in 4 layer denim tests, those are usually bullets that are either badly designed, or are driven to a higher velocity than they're built for. Or both.

[c_yeager]

The problem here is that the car tests actually involved surviving an accident. The bullet expansion tests are conducted in a way that doesnt accuratly determine their real-world performance.

[JERRY]

being a defensive driver goes a long way and is something most of the driving public does NOT do. the very same can be said for shot placement....which is first, followed by penetration, and a distant third would be expansion.

[orionengnr]

I get the impression that an agenda is at work.

If I am mistaken, excuse me.

Yeah, right.

[RecoilRob]

You are placed in a room, 12X12. Through the only doorway into that room 6 totally homicidal and criminally insane men will enter.....one every 30 seconds.

Each is armed with a razor-sharp machete and their entire life force is focused on hacking you into little, tiny, pieces.

These men vary in size from 5'10" to 6'5" and weigh between 165 and 365 lbs. Their dress will vary between heavily clad in leather and denim to totally naked.

You have a choice of only ONE handgun loaded with six rounds.

Which do you choose?

I would NOT choose ANY expanding handgun round in this example. Give me a good, solid Keith SWC....heavy for the caliber chosen (which will be the largest I can handle well)_ with enough penetration to exit the largest fellows back with a properly placed shot.

As was stated earlier, shot placement is MUCH more important than whether the bullet expands or not. Many times, expansion will result in failure with handguns of an otherwise perfectly placed shot.

Just my opinion....

[Deer Hunter]

What kind of sick fantasy went horribly wrong with you?!

I've seen bullets not expand completely when going into denim, but that doesn't mean that they'll just bounce off the bad guy while he, laughing, slices your head off. You're not giving enough credit to the bullet design. I would still like to have some kind of JHP when dealing with any two legged pest.

[BullfrogKen]

No magic bullet exists. Expansion and penetration are the two opposing ends of a compromise.


As long as I have something that delivers adequate penetration and doesn't disintergrate on its way there, I'm happy.


I'll worry about things I can control, like shot placement, control, and rapid hits.

[JohnBT]

And all this time I thought they used four layers in order to account for the very real possibility of shooting through an arm (two layers) first and then a chest pocket (two more layers.)

John

[RyanM]

And all this time I thought they used four layers in order to account for the very real possibility of shooting through an arm (two layers) first and then a chest pocket (two more layers.)

No, though that is the reason for the 12" minimum penetration requirement. Going through 4 layers of denim spaced out like that, only the first one would have much of an effect on expansion. By the time the bullet goes through the arm, it's already completely expanded. But 4 all in a row just represents a generic soft barrier, like a couch cushion, winter coat, teddy bear, etc.

---------------

You have a choice of only ONE handgun loaded with six rounds.

Which do you choose?

4" or 6" barreled .22 LR revolver loaded with "Acc'r'z'd" (or whatever that thing is called) CCI Mini-Mags. In that scenario, only brain shots would have any effect quickly enough. I wouldn't even count on a body shot with a 12 gauge to put a guy down fast enough that he can't run 12 feet and swing his arm.

--------------

The problem here is that the car tests actually involved surviving an accident. The bullet expansion tests are conducted in a way that doesnt accuratly determine their real-world performance.

According to who? People who have compared autopsy data with gelatin shooting data would disagree with you. http://www.btammolabs.com/fackler/winchester_9mm.pdf

There have been a ton more studies other than that one, comparing gelatin to living human tissue, and living pig tissue. The conclusion is and has always been, properly prepared gelatin is very, very similar.

[c_yeager]

According to who? People who have compared autopsy data with gelatin shooting data would disagree with you.

Did you read the methodology for that test? All instances in which a bullet hit a bone, or any part of the body other than the torso, or fully penetrated the torso were eliminated. Thats a whole lot of data that needs to be thrown out in order for geletin tests to be considered "accurate". Here is the problem, if you have to throw out real-world data to satisfy your laboratory simulations, then your simulations have fundamental problems.

So again, I mantain that geletin tests are not accurate predictors of real world performance. Even the articles published by the testing industry bear this out.

[JE223]

+1 RyanM.

c_yeager, I think there is an expression about not throwing out the baby with the bathwater? In much the same way, the issue of bones is addressed with tissue simulation. I don't know if you would consider me or my website part of the testing industry, since I don't get paid, but all bets are off when a bullet hits bone and this data should be discarded when evaluating the modeling capacity of ballistic gelatin to simulate living tissue.

Ballistic gelatin simulates muscle tissue and nothing else. It doesn't 'simulate the human body' as many have suggested. So, back to the bones issue, when a bullet hits bone, I gather, the bullet will generally deform and the bone will shatter - this may be a good thing or a bad thing IMO. It is bad because that perfectly placed shot that was going to transect the bad guys spine perhaps will not do so due to the effect of hitting a solid bone or other structure. On the other hand, hitting a bone is in no way a total failure of the bullet - that bone still was used by the BGs body to support something - perhaps it was the bone that was going to pull the trigger on the BGs gun and place a well-aimed shot where it should never go.

But I do agree with you, some work should be done to quantify/qualify the effects of bone/bullet interaction. Until then, the advice to 'fire, evaluate the target and be ready to fire again until the threat disappears' is the advice that sounds most reasonable to me ... :)

[c_yeager]

Ballistic gelatin simulates muscle tissue and nothing else. It doesn't 'simulate the human body' as many have suggested.

The entire point of my post was to point out that balistic testing is not analogous to auto-crash testing because the crash testing is a closer simulation of real world events, while the balistic geletin testing represnts only a very narrow set of parameters. That doesnt invalidate the testing, but it does limit the scope to which it can be applied to the real world. A crash does do a fairly accurate job of representing the factors of an auto collision, the gelatin tests do not, as they ignore significant variables that exist in the real world.

Also, if you throw out all instances in which a bullet fully penetrates the torso, it seems to me that you are throwing out a lot of instances in which the bullet did not expand or penetrate in a predictable way, if every gelatin tests shows reliable expansion and a fixed amount of penetration, and is an accurate representation of human tissue, one has to wonder how this even happens.

[Shawn Dodson]

4 Layers Denim: http://firearmstactical.com/tacticalbriefs/2006/04/02/0604-02a.htm

Gelatin testing (scroll down to "Extracts" section): http://firearmstactical.com/tacticalbriefs/2006/04/03/0604-03a.htm

[Navy joe]

I hit a steel wall going 90 head on, it wasn't fun, I had a separated sternum for a while, despite a 5 point harness designed to minimize such. That was a purpose built race car. No street car in the world would be identifiable after that. To apply your analogy correctly, we would all go shoot a charging rhino with our handgun carry ammo to determine which one has a "bullet that's overengineered to pass that test" In the end, much like I was driving a race car designed to survive such, we would all be stuffing .45-70s in our Smart Carry. Both passed a ridiculous test, both are entirely unsuitable for street use.

4 layers of denim is not "overengineering" it is an easily referenced, easily repeated, and relevant to real world use standard to evaluate hollowpoint handgun bullet performance such as plugging and expansion when passing through a barrier similar to what it would encounter in real life prior to entering soft tissue. Repeatable and relevant, just like that concrete wall we run cars into at 35 mph. Relevant, anyone in a cool climate will often wear more than 4 layers denim equivalent. I don't see the over engineering. I don't see the fuss either, big, heavy fast hollowpoint (230 gr Golden Saber) ought to do nicely whether it expands or not.

[CTI1USNRET]

Navy joe - what he said. I carry 230 gr Golden Sabers.

And, as far as cars crumpling goes, I've always wanted to replace the bumpers on my pickup with 6x6's. Let the other car do the crumpling.

[Borachon]

6 guys every 30 seconds who are coming to hack me to death with a razor sharp machete?

Okay...

Shoot the first guy six times. Take his machete. Lop the heads off everyone else as they come thru the door. :D

[R.H. Lee]

Even if your bullet penetrates 4 layers of denim (an most major calibers will) you still have to hit something vital to stop your attacker. Good bullet design won't make up for poor bullet placement. We need emphasize the use of skill more, and de-emphasize the notion that you can buy your way into superior self defense.

[gudel]

how many of you here actually wear 4 layers of denim in your regular day? :confused:

[Biker]

I dunno, but I often wear two layers of leather with a layer of denim underneath.
Biker

[RyanM]

2 people completely missing the point in a row. A new record.

Even if your bullet penetrates 4 layers of denim (an most major calibers will) you still have to hit something vital to stop your attacker. Good bullet design won't make up for poor bullet placement. We need emphasize the use of skill more, and de-emphasize the notion that you can buy your way into superior self defense.

Any bullet will penetrate 4 layers of denim. But very few will expand if they hit a person or block of gelatin immediately afterwards.

-------------

how many of you here actually wear 4 layers of denim in your regular day?

Read the post again. :scrutiny:

[R.H. Lee]

Any bullet will penetrate 4 layers of denim. But very few will expand if they hit a person or block of gelatin immediately afterwards.
Talk about missing the point. Penetration is an essential component of bullet performance. Bullet expansion is not. Unless the bullet penetrates deep enough to hit some thing vital, like an artery or major organ, expansion is meaningless.

[JohnBT]

"heavy denim (weight 16 ounces per square yard)."

Thank you for the link, that answers my question.

A little surfing around shows that many jeans are 10 to 12 ounces, with some 14.

I found one jean collector site where they were talking about some hard to find jeans made with 21-ounce denim. To put that in perspective, one poster said, "Rodeo standard is either 16 or 17 ounces, I forget which."

U.S. Customs says heavy denim is 14 or 16.

John

[RecoilRob]

Great answer!! THAT is thinking outside of the box!