Page 4 of 4 FirstFirst 1234
Results 61 to 77 of 77
  1. #61
    Arcus is offline Junior Member
    Join Date
    Feb 2008
    Location
    Colorado
    Posts
    34

    Bullet expansion most important...

    Quote Originally Posted by Mike Barham View Post
    A bullet that exits creates two holes instead of one. This theoretically increases the chance of pneumothorax/hemothorax, which may be more likely to cause death than the slightly greater permanent wound cavity created by an expanded JHP, depending on the location of the wound.
    In reference to this and other previous posts re. degree of penetration, my personal experience in the operating room is that for a given energy, a bullet which expands and stops, expending all of its energy inside a body, will do more internal damage. Those which do not and continue out of the body in a through-and-through fashion without expansion and a sizeable exit wound do not cause meaningful additional bleeding with the exit wound. In the absence of a large exit wound, the most important and lethal sources of flood loss occur internally as caused by damage to arteries and well perfused organs, e.g. heart, kidney, spleen, liver, lungs. I've excluded the brain from that list for an obvious reason. It is entirely possible to hemorrhage most of ones total blood volume (~ 5L ) into the abdomen alone.

  2. #62
    Join Date
    Aug 2007
    Location
    Lexington
    Posts
    1,083
    Quote Originally Posted by Arcus View Post
    In reference to this and other previous posts re. degree of penetration, my personal experience in the operating room is that for a given energy, a bullet which expands and stops, expending all of its energy inside a body, will do more internal damage. Those which do not and continue out of the body in a through-and-through fashion without expansion and a sizeable exit wound do not cause meaningful additional bleeding with the exit wound. In the absence of a large exit wound, the most important and lethal sources of flood loss occur internally as caused by damage to arteries and well perfused organs, e.g. heart, kidney, spleen, liver, lungs. I've excluded the brain from that list for an obvious reason. It is entirely possible to hemorrhage most of ones total blood volume (~ 5L ) into the abdomen alone.
    Very good point. And, internal bleeding is much more difficult to stop than a surface wound, and many times impossible.

    I think it would be safe to say that a FMJ that does damage or rupture arteries or other vital organs necessary to maintain life in a human being, and that does exit would be a more lethal bullet.

    On the flip side, I think it would also be safe to say that a JHP, in the grand scheme of things, is more lethal in that its expansion and total energy transfer inside the human body gives it a MUCH higher chance of causing damage to arteries or other vital organs (i.e. it expands and takes out the aortal wall when the FMJ does not).

    It's a compromise. If the FMJ hits the right spots and exits, it's deadlier. If it misses where an expanded JHP would hit or doesn't expend enough of its energy to cause significant damage where an expanded JHP would, it's not deadlier. However, the chance of a JHP causing fatal damage and/or blood loss is more likely than a FMJ. In actuality they are two different arguments.

  3. #63
    Mike Barham's Avatar
    Mike Barham is offline Senior Member
    Join Date
    Mar 2006
    Location
    Arizona, baby!
    Posts
    5,081
    Maybe I am misunderstanding the physical mechanisms involved, but how does "expending its energy in the target" do anything? Energy is just the ability to do work - in this case, making a hole and expanding the bullet. A bullet that penetrates to the same depth and expands to the same diameter will do the same damage to the body, regardless of how much energy it uses to do so.

    I agree with the point about internal bleeding, hence my comment about it depending on the location of the wound.
    Employed by Galco Gunleather - www.galcogunleather.com / Veteran OEF VIII

    Donate to the Christian and Stephanie Nielson Recovery fund: http://www.nierecovery.com/.

    All opinions, particularly those involving politics and Glocks, are mine and not Galco's.

  4. #64
    Join Date
    Aug 2007
    Location
    Lexington
    Posts
    1,083
    Quote Originally Posted by Mike Barham View Post
    Maybe I am misunderstanding the physical mechanisms involved, but how does "expending its energy in the target" do anything? Energy is just the ability to do work - in this case, making a hole and expanding the bullet. A bullet that penetrates to the same depth and expands to the same diameter will do the same damage to the body, regardless of how much energy it uses to do so.

    I agree with the point about internal bleeding, hence my comment about it depending on the location of the wound.
    I think the energy transfer is a valid point. If a non-expanding FMJ perforates a target, it has kinetic energy carrying it through, and then further once it exits. While an expanding JHP offers a larger, wider wound channel, the expansion acts as a brake to stop it from exiting.

    Think of it this way. Say you have two 124gr bullets, one FMJ, one JHP. Say both have equal terminal velocity, energy, sectional density, and momentum. The only difference is that one expands, and one does not. Say the FMJ perforates the person and exits with exactly half of its original terminal V, E, SD, and M. Because it did not expand, it didn't have the increased SA (surface area) to expend all of its energy. Say the JHP expands and stops in the person. Because of expansion, the SA is increased, so being that it's wider, it can cover a larger area of body tissue and expend its energy. Similarly with snowshoes. If you jump on two feet of snow in boots, you'll punch through. With snowshoes, the weight (like the energey of the bullet) is spread over a wider area, and you stay on top. Higher sectional density means it has less SA to actually hit resistance (body tissue).

    So in essence, you could have a non-expanding 9mm (.36) FMJ that expends 300ft/lbs and exits with 150ft/lbs of energy (450ft/lbs total). Or, an expanding 9mm (.36) JHP that mushrooms to .55-60 and expends all 450ft/lbs into the body. The high sectional density of the FMJ doesn't give it enough SA to stop in the body...there isn't enough resistance on its frontside to bring it to a halt in a person. The JHP that mushrooms increases its SA, meaning it has more tissue to punch through with the same V, E, and bullet weight, so the extra tissue it crushes causes it to lose all of its energy.

    I think the whole thing about energy transfer is that full energy transfer means it has contributed all of its kinetic energy into crushing bodily tissue and/or organs, meaning maximum internal damage.

  5. #65
    Arcus is offline Junior Member
    Join Date
    Feb 2008
    Location
    Colorado
    Posts
    34
    Quote Originally Posted by Mike Barham View Post
    Maybe I am misunderstanding the physical mechanisms involved, but how does "expending its energy in the target" do anything? Energy is just the ability to do work - in this case, making a hole and expanding the bullet. A bullet that penetrates to the same depth and expands to the same diameter will do the same damage to the body, regardless of how much energy it uses to do so.

    I agree with the point about internal bleeding, hence my comment about it depending on the location of the wound.
    Ok, just to make sure I'm communicating precisely and also not misunderstanding Mike or anyone else... the energy I'm referring to is the same as muzzle energy except inside the body of the target BG. It's the energy the bullet retains upon arriving at the target. Kinetic energy I believe is = one half times the product of mass times velocity squared. (sorry there doesn't seem to be an equation editor on this forum ) That's why the .45ACP is a better SD round than a .22LR - more energy to be expended in and do damage to a BG's arteries and internal organs.

    As for ball vs. JHP, expansion inside the body, yadda yadda yadda... Mike makes the point that energy can be converted to work, or in geekspeak, force over a distance. In a gunfight, a bullet's energy is best spent forcing its way through vital structures. A larger bullet, or one which has deformed to become larger, will strike more structures on its way into a body if it has enough energy to continue its forward progress.

    Hmph, as is my habit I went and made that more complicated than it needed to be. Rephrasing, if a bullet exits a BG that means it still had kinetic energy which could have been converted to internal damage had it deformed to a greater degree and come to a stop inside the BG. That sounds clearer.

  6. #66
    Join Date
    Aug 2007
    Location
    Lexington
    Posts
    1,083
    Quote Originally Posted by Arcus View Post
    Hmph, as is my habit I went and made that more complicated than it needed to be. Rephrasing, if a bullet exits a BG that means it still had kinetic energy which could have been converted to internal damage had it deformed to a greater degree and come to a stop inside the BG. That sounds clearer.
    The way I see it, "energy transfer" itself does not cause more internal damage. The fact that it is able to transfer 100% of its kinetic energy is because it made contact with enough tissue and/or organs to completely stop the bullet, which means it induced maximum internal damage to the body.

    In other words, complete energy transfer does not mean the bullet caused maximum damage. It's the other way around...the bullet causing maximum damage means the bullet transferred all of its kinetic energy. The only way a bullet can transfer 100% of its energy to a person is when the bullet has enough resistance to come to a complete stop. And the only way it can have enough resistance is if it engages enough tissue to bring it to a stop.

    Say a 9mm bullet expanded to 300% diameter upon impact. It would demolish a huge portion of tissue, but wouldn't penetrate very far. All of its energy would be contained within a few inches, creating a very wide, disgusting wound, but not a deep one. The same 9mm that does not expand and exits the person would cause a straight-through wound, but would still have energy left over that could've damaged more tissue had it expanded. The trick to JHPs is finding one that expands to a maximum to damage the most tissue, but is still able to penetrate far enough to hit vital organs and/or the CNS.

  7. #67
    Dredd is offline Member
    Join Date
    Feb 2008
    Posts
    267
    Quote Originally Posted by Mike Barham View Post
    Maybe I am misunderstanding the physical mechanisms involved, but how does "expending its energy in the target" do anything? Energy is just the ability to do work - in this case, making a hole and expanding the bullet. A bullet that penetrates to the same depth and expands to the same diameter will do the same damage to the body, regardless of how much energy it uses to do so.

    I agree with the point about internal bleeding, hence my comment about it depending on the location of the wound.
    Perhaps it's enough energy deposit to cause an involuntary muscle reaction and in a best case circumstance cause the bad guy to collapse? I'm no doctor or physicist so I don't know. It probably has more to do with the mythological 1 shot and he's down idea.

  8. #68
    Dredd is offline Member
    Join Date
    Feb 2008
    Posts
    267
    Quote Originally Posted by fivehourfrenzy View Post
    The way I see it, "energy transfer" itself does not cause more internal damage. The fact that it is able to transfer 100% of its kinetic energy is because it made contact with enough tissue and/or organs to completely stop the bullet, which means it induced maximum internal damage to the body.

    In other words, complete energy transfer does not mean the bullet caused maximum damage. It's the other way around...the bullet causing maximum damage means the bullet transferred all of its kinetic energy. The only way a bullet can transfer 100% of its energy to a person is when the bullet has enough resistance to come to a complete stop. And the only way it can have enough resistance is if it engages enough tissue to bring it to a stop.

    Say a 9mm bullet expanded to 300% diameter upon impact. It would demolish a huge portion of tissue, but wouldn't penetrate very far. All of its energy would be contained within a few inches, creating a very wide, disgusting wound, but not a deep one. The same 9mm that does not expand and exits the person would cause a straight-through wound, but would still have energy left over that could've damaged more tissue had it expanded. The trick to JHPs is finding one that expands to a maximum to damage the most tissue, but is still able to penetrate far enough to hit vital organs and/or the CNS.
    Your last sentence is exactly what the FBI tests. They test various pistol calibers and check the results they obtain in both expansion and penetration. They also examine the possible wound channel created. They then recommend certain bullets be used by field agents. I believe (please don't quote me) that the FBI seeks a bullet that can expand reliably and retain a majority of it's weight after expansion while penetrating 12"-14" and not much further (due to risk of exiting).

    They recommend Speer Gold dot 124gr +p, Winchester Ranger T 127gr +p+ among others.

    Here's a link to some of their test data. I don't know how complete this test is and I understand the information obtained is a few years old, but here it is. Click on the Tactcal Brief Links for some personal defense ammo ballistic results with pictures of the expanded bullet. http://www.firearmstactical.com/tactical.htm

  9. #69
    Arcus is offline Junior Member
    Join Date
    Feb 2008
    Location
    Colorado
    Posts
    34

    Excellent clarification!

    Quote Originally Posted by fivehourfrenzy View Post
    ...The fact that it is able to transfer 100% of its kinetic energy is because it made contact with enough tissue and/or organs to completely stop the bullet, which means it induced maximum internal damage to the body...

    ...Say a 9mm bullet expanded to 300% diameter upon impact. It would demolish a huge portion of tissue, but wouldn't penetrate very far. All of its energy would be contained within a few inches, creating a very wide, disgusting wound, but not a deep one. The same 9mm that does not expand and exits the person would cause a straight-through wound, but would still have energy left over that could've damaged more tissue had it expanded. The trick to JHPs is finding one that expands to a maximum to damage the most tissue, but is still able to penetrate far enough to hit vital organs and/or the CNS.
    Bingo! One of my biggest faults in this type of conversation is being too technical and unclear. You've captured it well here. The greater the muzzle energy of the round the more it needs to deform to keep the energy inside the BG and not something or someone behind him.

  10. #70
    Join Date
    Aug 2007
    Location
    Lexington
    Posts
    1,083
    Quote Originally Posted by Arcus View Post
    The greater the muzzle energy of the round the more it needs to deform to keep the energy inside the BG and not something or someone behind him.
    And when a bullet transfers all of its energy to the BG, that means it's damaged the maximum amount of tissue possible with the given bullet. Once that's accomplished, a big determinant of how effective the bullet is is to look at penetration versus expansion. More expansion = less penetration, and less expansion = more penetration. Once you have enough penetration to make the bullet stop in the BG, then you work with expansion properties. If it's not penetrating far enough, decrease expansion. If it's penetrating more than necessary, increase expansion.

    I believe the FBI standards are as follows:

    6" or less = insufficient
    7-12" = sufficient
    13-16" = optimal
    16"+ = sufficient, but not if it overpenetrates

    I think I'm a bit off on my numbers, but it's pretty close.

    Gold Dots pwn.

  11. #71
    Mike Barham's Avatar
    Mike Barham is offline Senior Member
    Join Date
    Mar 2006
    Location
    Arizona, baby!
    Posts
    5,081
    Okay, I agree with the energy transfer statement the way it's been rephrased. Again, it's just the ability to do the work of expanding the bullet and burrowing through the body. If we mean that "maximum energy transfer" means expanding the bullet as much as possible while still stopping in the body at a depth that damages the maximum number of vital organs, then yes, it is a good thing.

    I just don't think there's anything magical about "energy transfer," which was one of the silly "stopping power" buzzwords (buzz phrases?) of the 1980s. It's more about the size of the wound cavity, which is directly related to the size of the expanded bullet and the depth of penetration.

    I carry JHPs and encourage everyone to do the same.
    Employed by Galco Gunleather - www.galcogunleather.com / Veteran OEF VIII

    Donate to the Christian and Stephanie Nielson Recovery fund: http://www.nierecovery.com/.

    All opinions, particularly those involving politics and Glocks, are mine and not Galco's.

  12. #72
    Join Date
    Aug 2007
    Location
    Lexington
    Posts
    1,083
    Quote Originally Posted by Mike Barham View Post
    I carry JHPs and encourage everyone to do the same.
    How are Hydra-shoks different than standard JHPs? I know Gold Dots use uni-core technology to keep the jacket from separating from the core, which is the most common cause of a JHP failing to expand.

  13. #73
    Mike Barham's Avatar
    Mike Barham is offline Senior Member
    Join Date
    Mar 2006
    Location
    Arizona, baby!
    Posts
    5,081
    Hydra-Shoks use a central post in the hollow cavity that supposedly channels pressure better for expansion. However, they don't seem to do any better or worse than other modern JHPs. For a while, they were the hot thing, but now they're just another bullet.
    Employed by Galco Gunleather - www.galcogunleather.com / Veteran OEF VIII

    Donate to the Christian and Stephanie Nielson Recovery fund: http://www.nierecovery.com/.

    All opinions, particularly those involving politics and Glocks, are mine and not Galco's.

  14. #74
    Dredd is offline Member
    Join Date
    Feb 2008
    Posts
    267
    Quote Originally Posted by Mike Barham View Post
    Hydra-Shoks use a central post in the hollow cavity that supposedly channels pressure better for expansion. However, they don't seem to do any better or worse than other modern JHPs. For a while, they were the hot thing, but now they're just another bullet.
    Then you have the famous "Black talon" from Winchester that was taken off the market and had the black coating removed. Current Winchester Ranger T rounds are this same bullet. Some claim it's better than before. It was labeled as a "cop killer" bullet for a while I believe.

    There is also the Barnes X Bullet used by Corbon in their DPX line which some people claim to have success with in testing.

    Yet, there is no actual evidence that any of these are better at stopping a person than the others. I say, find a load you can group well, fired reliably in your gun, feeds reliable, doesn't have failures, and you can get easily. Then you use that one. I don't have enough time to test every single thing out there

    Personally I like Gold Dot, some people only use Corbon, some people only use Federal or Hornady or Winchester Ranger. Then you have different weights. Some people like a light and fast bullet, some people like a heavier and slower bullet. You have +p and +p+ etc as well. It's enough to make you go crazy trying to decide what to use. So my solution was to get a few of each and shoot a grouping of about 5 rounds at a target. Which one felt best to me, was there any issues? Did I hit my intended target?

    The answer was yes to each question with every load I tried. I don't have means to test ballistics and expansion etc. However, I could use some online resources to get an idea of what worked well. Based on that information I made a decision based on what I could easily obtain, what the price was, how well I shot it, and if it worked reliably in my gun.

  15. #75
    Mike Barham's Avatar
    Mike Barham is offline Senior Member
    Join Date
    Mar 2006
    Location
    Arizona, baby!
    Posts
    5,081
    Dredd is on the money. People spend way too much time poring over the minutiae of one premium bullet versus the next. They all work well if they are shot well.

    There are more important things to think about when it comes to self-defense. I suggest everyone just pick the premium round that works in their gun and move on.
    Employed by Galco Gunleather - www.galcogunleather.com / Veteran OEF VIII

    Donate to the Christian and Stephanie Nielson Recovery fund: http://www.nierecovery.com/.

    All opinions, particularly those involving politics and Glocks, are mine and not Galco's.

  16. #76
    Dredd is offline Member
    Join Date
    Feb 2008
    Posts
    267
    Quote Originally Posted by Mike Barham View Post
    Dredd is on the money. People spend way too much time poring over the minutiae of one premium bullet versus the next. They all work well if they are shot well.

    There are more important things to think about when it comes to self-defense. I suggest everyone just pick the premium round that works in their gun and move on.
    I should mention that I tested Double Tap Gold Dot 124gr +p, Speer Gold Dot 124gr +p, some Hornady Tap, Winchester Ranger T 127gr +p+, Corbon DPX and standard 115gr +p, Hydrashok 135gr and 115gr +p+.

    Tested in a Glock 17, Smith & Wesson M&P9, Springfield XD9, HK P30, HK USPc 9mm, and a Beretta 92FS. Every round fired reliably, fed fine, and generally had no issues. So I would wager that any quality gun would handle any quality ammo with ease. I have only had any issues with certain brands of practice ammo in any of the listed guns(low power cheap ammo and reloads). I would have to say that most ammo marketed for personal defense is manufacturerd and loaded to tighter tolerances and QA'd a bit more thoroughly. Still, I would test a magazine to be sure.

    I only own the HK P30, but had access to the others through a couple friends who went in on the ammo purchases with me to split the cost and some of the testing.

  17. #77
    Join Date
    Aug 2007
    Location
    Lexington
    Posts
    1,083
    My Doubletaps came in the mail yesterday. They're pretty.

Page 4 of 4 FirstFirst 1234

Links

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Search tags for this page

9mm 4gr unique
,

9mm favorite load

,
9mm load data unique
,
best 9mm ammo for ruger p95
,

favorite 9mm load

,

favorite 9mm loads

,
favorite 9mm target loads- high accuracy
,
favorite9mm accuracy loads
,
most accurate 9mm load
,
most accurate ammo for p30 9mm
,
recommended bullit oal for 9mm 115 gr
,
what ammo does ruger p95 used
Click on a term to search for related topics.