Why JHP over FMJ?

[Chris-bob]

So I had the hard drives from two computers from work that needed to be "destroyed" and took them out back.
Both were shot from 7' away with my KelTec PF9

This one was shot twice with Hornady Critical Duty 135gr +P.

Here is the damage.

This one was shot 3 times. The bottom two(smaller holes) were Sellier & Bellot 124gr FMJ, the third, larger hole closest to the middle was another Critical Duty.

Here is a close up.

The S&B made clean holes. The Hornady made the larger hole.

Left is the Hornady, right is the S&B.

 

[Chris-bob]

I understand that the *FMJ* will have more penetration supposedly and less expansion. But the Hornady just doesn't seem that great...

 

[Bobson]

Flesh isn't metal. The expansion you see in the S/B FMJ isn't representative of the type of expansion you'll see in FMJ going through flesh. Not anywhere near reliably, at least.

I understand that the FMJ will have more penetration supposedly and less expansion

Fixed that for you. I assume it was a typo.

 

[Chris-bob]

Yeah, that was a typo.

I was very surprised by the two shots at the one hard drive. I expected them to be more like the third shot and penetrate with a larger hole. Not be stopped completely. The FMJ holes are very clean. I was expecting that.

 

[45_auto]

I was very surprised by the two shots at the one hard drive. I expected them to be more like the third shot and penetrate with a larger hole. Not be stopped completely.

Take a look at what is behind the thin sheet metal cover. The ones that DIDN'T penetrate ran up against a chunk of solid steel like a motor, platter bracket, etc.

There's a reason that "shot placement" is the most important factor in bullet effectiveness.

 

[kayakersteve]

Unless you hunt metal hard drives or plan on defending yourself against a full on attack by metal, your theory is flawed. The reason we test in ballistic gel is that it mimics flesh, muscle and bone.

 

[herrwalther]

Unless you hunt metal hard drives or plan on defending yourself against a full on attack by metal, your theory is flawed. The reason we test in ballistic gel is that it mimics flesh.

Fixed that for you. Standard ballistic gelatin is designed to mimic flesh, but not sporadic pockets of materials of varying densities such as muscles, large blood vessels, organs, and bone. Now shooting something a little bit more realistic such as cadavers or meat chunks provide a more realistic expectation of how rounds will behave inside living tissue. But still nothing compares to how a living target will react: blood and adrenaline going to the muscles for fight or flight, panic and fear of the target etc.

 

[sixgunner455]

Hollow points are going to reduce penetration. The military uses FMJ because of two things: they want to be in compliance with international laws on warfare, and they want to be able to penetrate more reliably through more barriers. The hard drive penetration shows that FMJ can't always penetrate through barriers, but it does so much more reliably than hollow points.

In civilian life, I carry hollow points because if I have to use my weapon to defend myself, I want to quickly incapacitate someone who probably doesn't have a hard metal plate in his shirt pocket.

 

[RedBowTies88]

Some of us live in states that highly regulate the transportation and usage of expanding ammo..

so it's just far less of a hassle to use FMJ

 

[JRH6856]

I've got a lot of old hard drives. I think I'll see if I can use them in a ballistic vest.

 

[Certaindeaf]

Your hard drive is shielded with around 1/4" of bone, unlike the Terminator.

 

[JShirley]

You can remove "penetrate more reliably through barriers" as a reason the US military uses FMJ. The MK318 is the new round adopted by the USMC. It is OTM.

The US military has been granted legal approval to use HP (OTM) rounds only by claiming the open tips are primarily a ballistic feature.

Why HP? More effective against threats, with less shoot-through liability.

John

 

[Chris-bob]

I've seen the results of JHP in ballistic gellatin, but does anyone have a quick link to the results with FMJs? I understand the difference between flesh and most barriers(ie hard drives). Another question would be whether JHPs are better or worse than non-jacketed HPs...

 

[splattergun]

wish I could step out back on my break and pop a few rounds.

 

[Paul24]

So many hard drives and so little time.

 

[col_temp]

Would be interesting to see what happens. I have a bunch of old drives to get rid of for a client.
Think I'll repeat the test and see! Would be interesting to see what the 00 buck does from the 12G!

 

[Frank Ettin]

Why JHP for self defense applications? Because they are likely to be more effective. For a full discussion, see the following:

1. The goal is to stop the assailant.
   
   
2. There are four ways in which shooting someone stops him:
   
   
   • psychological -- "I'm shot, it hurts, I don't want to get shot any more."
     
     
   • massive blood loss depriving the muscles and brain of oxygen and thus significantly impairing their ability to function
     
     
   • breaking major skeletal support structures
     
     
   • damaging the central nervous system.
   
   Depending on someone just giving up because he's been shot is iffy. Probably most fights are stopped that way, but some aren't; and there are no guarantees.
   
   Breaking major skeletal structures can quickly impair mobility. But if the assailant has a gun, he can still shoot. And it will take a reasonably powerful round to reliably penetrate and break a large bone, like the pelvis.
   
   Hits to the central nervous system are sure and quick, but the CNS presents a small and uncertain target. And sometimes significant penetration will be needed to reach it.
   
   The most common and sure physiological way in which shooting someone stops him is blood loss -- depriving the brain and muscles of oxygen and nutrients, thus impairing the ability of the brain and muscles to function. Blood loss is facilitated by (1) large holes causing tissue damage; (2) getting the holes in the right places to damage major blood vessels or blood bearing organs; and (3) adequate penetration to get those holes into the blood vessels and organs which are fairly deep in the body. The problem is that blood loss takes time. People have continued to fight effectively when gravely, even mortally, wounded. So things that can speed up blood loss, more holes, bigger holes, better placed holes, etc., help.
   
   So as a rule of thumb --
   
   
   • More holes are better than fewer holes.
     
     
   • Larger holes are better than smaller holes.
     
     
   • Holes in the right places are better than holes in the wrong places.
     
     
   • Holes that are deep enough are better than holes that aren't.
     
     
   • There are no magic bullets.
   
   
3. With regard to the issue of psychological stops see
   
   
   • this study by Greg Ellifritz.
     
     As Ellifritz note in his discussion of his "failure to incapacitate" data (emphasis added):

     ...Take a look at two numbers: the percentage of people who did not stop (no matter how many rounds were fired into them) and the one-shot-stop percentage. The lower caliber rounds (.22, .25, .32) had a failure rate that was roughly double that of the higher caliber rounds. The one-shot-stop percentage (where I considered all hits, anywhere on the body) trended generally higher as the round gets more powerful. This tells us a couple of things...
     
     In a certain (fairly high) percentage of shootings, people stop their aggressive actions after being hit with one round regardless of caliber or shot placement. These people are likely NOT physically incapacitated by the bullet. They just don't want to be shot anymore and give up! Call it a psychological stop if you will. Any bullet or caliber combination will likely yield similar results in those cases. And fortunately for us, there are a lot of these "psychological stops" occurring. The problem we have is when we don't get a psychological stop. If our attacker fights through the pain and continues to victimize us, we might want a round that causes the most damage possible. In essence, we are relying on a "physical stop" rather than a "psychological" one. In order to physically force someone to stop their violent actions we need to either hit him in the Central Nervous System (brain or upper spine) or cause enough bleeding that he becomes unconscious. The more powerful rounds look to be better at doing this....

   • Also see the FBI paper entitled "Handgun Wounding Factors and Effectiveness", by Urey W. Patrick. Agent Patrick, for example, notes on page 8:

     ...Psychological factors are probably the most important relative to achieving rapid incapacitation from a gunshot wound to the torso. Awareness of the injury..., fear of injury, fear of death, blood or pain; intimidation by the weapon or the act of being shot; or the simple desire to quit can all lead to rapid incapacitation even from minor wounds. However, psychological factors are also the primary cause of incapacitation failures.
     
     The individual may be unaware of the wound and thus have no stimuli to force a reaction. Strong will, survival instinct, or sheer emotion such as rage or hate can keep a grievously wounded individual fighting....

   
   
4. And for some more insight into wound physiology and "stopping power":
   
   
   • Dr. V. J. M. DiMaio (DiMaio, V. J. M., M. D., Gunshot Wounds, Elsevier Science Publishing Company, 1987, pg. 42, as quoted in In Defense of Self and Others..., Patrick, Urey W. and Hall, John C., Carolina Academic Press, 2010, pg. 83):

     In the case of low velocity missles, e. g., pistol bullets, the bullet produces a direct path of destruction with very little lateral extension within the surrounding tissue. Only a small temporary cavity is produced. To cause significant injuries to a structure, a pistol bullet must strike that structure directly. The amount of kinetic energy lost in the tissue by a pistol bullet is insufficient to cause the remote injuries produced by a high-velocity rifle bullet.

     
     
   • And further in In Defense of Self and Others... (pp. 83-84, emphasis in original):

     The tissue disruption caused by a handgun bullet is limited to two mechanisms. The first or crush mechanism is the hole that the bullet makes passing through the tissue. The second or stretch mechanism is the temporary wound cavity formed by the tissue being driven outward in a radial direction away from the path of the bullet. Of the two, the crush mechanism is the only handgun wounding mechanism that damages tissue. To cause significant injuries to a structure within the body using a handgun, the bullet must penetrate the structure.

     
     
   • And further in In Defense of Self and Others... (pp. 95-96, emphasis in original):

     Kinetic energy does not wound. Temporary cavity does not wound. The much-discussed "shock" of bullet impact is a fable....The critical element in wounding effectiveness is penetration. The bullet must pass through the large blood-bearing organs and be of sufficient diameter to promote rapid bleeding....Given durable and reliable penetration, the only way to increase bullet effectiveness is to increase the severity of the wound by increasing the size of the hole made by the bullet....

   
   
5. Urey Patrick was in the FBI for some 24 years, 12 of which were in the firearms training unit where he rose to the position of Assistant Unit Chief. John Hall is an attorney who spent 32 years in the FBI, including serving as a firearms instructor and a SWAT team member.
   
   
6. So a quality JHP bullet which is likely to expand and make a larger hole than its caliber would generally be a better choice than a FMJ bullet of the same caliber, which will not expand and therefore will make a hole no larger than its caliber -- as long as each penetrated adequately. Modern, quality JHP ammunition in appropriate cartridges will generally expand adequately.

 

[Old_Gun_Hand]

Problem is that most gun owners never see what bullets do in real life against human flesh. I have seen a .22lr stop a big man in his tracks and several .45's not slow someone down. Seen bullets stopped by all sorts of things and not stopped at all.

Seen a lot of strange things like bullets hitting an arm and exiting the neck, etc.. You just never know. My point is do not rely on gel, hard drive, watermelon and water tests. They are not good indicators of what you bullet will do in real life in flesh and bone. Not only the bullet but the angle of entry can have a great effect on what the bullet does.

 

[Chris-bob]

Great post Frank. Good reading. I'm not saying I won't use JHPs anymore, it just really surprised me when those two shots didn't go through the outer layer. Great responses. Wish I had more time and money for more plunking...I mean 'tests'.

 

[RhinoDefense]

The JHP was developed by SuperVel company and their marketing strategy to get law enforcement sales was to create an overblown proportion of pass-throughs in police shootings using FMJ bullets. The agencies bought into it and now that's the standard defensive bullet style today.

 

[JRH6856]

The JHP was developed by SuperVel company

Jacketed hollow points had been around long before Super Vel came on the scene, but they found their greatest success in rifle ammo because high velocity was required for reliable expansion. What Lee Jurras did with Super Vel was use a lightweight JHP in an attempt to achieve the velocity necessary for expansion in a handgun. In doing so, he sacrificed mass (and penetration) to achieve speed (and expansion) and whether or not he was successful enough for the performance to be reliable enough for defensive purposes was a raging controversy.

Since then, JHP bullet design has focused on achieving reliable expansion at lower velocities. The effort has generally been successful.

 

[RhinoDefense]

The effort has generally been successful.

Unfortunately not as successful as cast bullets have always been.

 

[backbencher]

Just found out a colleague had been shot w/ a FMJ 9mm in his leg. Went straight through. It delayed his deployment by approx 1 month.

 

[frankenstein406]

Take a look at what is behind the thin sheet metal cover. The ones that DIDN'T penetrate ran up against a chunk of solid steel like a motor, platter bracket, etc.

There's a reason that "shot placement" is the most important factor in bullet effectiveness.

There's almost no steel in a hdd. It's pretty much all aluminium.

 

[DSling]

wish I could step out back on my break and pop a few rounds.

No need to. Just do an office pop.

But seriously I had a 9mm in another life that almost got me killed. When I switched to the 45 it was way more effective. Fast fwd 10 years and I can say that I like 9mm better then the 45 I had. It's is all about ammo. It has nothing to do with caliber for me.