Penetration vs Expansion

Discussion in 'Glock Forum' started by djg1965, Sep 27, 2020.

  1. Lucian_253

    Lucian_253 Well-Known Member Supporter

    Ammo wars are always just one controversial comment away, lol!!
     
    NWG40 and Danzig like this.
  2. j102

    j102 Well-Known Member

    3,756
    743
    Thanks Bob!
    The paragraph above addresses one of the most important points of the discussion.
     
    Lucian_253 and rbbeers like this.

  3. j102

    j102 Well-Known Member

    3,756
    743
    Definitely! lol
     
  4. Mee too..Also G9, same concept.
     
    NWG40 likes this.
  5. rbbeers

    rbbeers Well-Known Member Lifetime Supporting Member

    3,653
    4,539
    Considering the following...

    380 ACP 68 Grain Xtreme Defender
    https://www.underwoodammo.com/colle...-grain-xtreme-defender?variant=18785708179513

    BRAND:UNDERWOOD AMMO

    SKU:638

    TECHNICAL INFORMATION
    • Caliber: 380 ACP
    • Bullet Weight: 68 Grains
    • Bullet Style: Lehigh Defense Xtreme Defense
    • Case Type: Ducta-Bright 7a Nickel Brass
    BALLISTICS INFORMATION
    • Muzzle Velocity: 1300 fps
    • Muzzle Energy: 255 ft lbs
    • Penetration: 14 inches
    ... I'm curious as to how the 14" of penetration was established.

    If indeed the penetration is in bare ballistic gelatin, given the bullet's relatively low weight and momentum (68 gr @ 1300 fps, 88 PF), I'm curious as to how it would perform when tested with barriers... and if, in reality, the heavier 'Penetrator' (90 gr @ 1100 fps, 99 PF) would actually perform better.

    Just a thought... :)

    Best regards,

    Bob
     
    Last edited: Sep 29, 2020
    NWG40 and Southlake like this.
  6. NWG40

    NWG40 Well-Known Member Supporter

    The way they accomplish that is using a FTM (Fluid Transfer Monolithic) bullet that has an optimized flute geometry. Just a fancy way of saying it has a cross hatch on the meplat. The defenders have a bigger cross hatch than that of the penetrators which are smaller. In either case since both are solid copper, the PWC is larger than a hollowpoint and virtually barrier blind.
    Note: there's a notation that they can have 18" of penetration per FBI guidelines.
     
  7. rbbeers

    rbbeers Well-Known Member Lifetime Supporting Member

    3,653
    4,539
    Yep! I do indeed understand 'all the above'. (But, in reality, there's no such thing as 'barrier blind'... some bullets are simply less affected than others.) ;) :D

    Nonetheless, I'd still like to see the results of actual barrier testing in accordance with the FBI Penetration Tests presented in post #20.

    Best regards,

    Bob
     
  8. Lucian_253

    Lucian_253 Well-Known Member Supporter

    I should try the penetrators maybe. I just cannot run +P in the lcp2.
     
    rbbeers likes this.
  9. rbbeers

    rbbeers Well-Known Member Lifetime Supporting Member

    3,653
    4,539
    Yep! I understand. :)

    The numbers I posted were for the standard pressure cartridges. :D

    Best regards,

    Bob
     
  10. Lucian_253

    Lucian_253 Well-Known Member Supporter



    Not underwood but Leighi Xtreme defenders 13” through denim.
     
    NWG40 and rbbeers like this.
  11. rbbeers

    rbbeers Well-Known Member Lifetime Supporting Member

    3,653
    4,539
    It appears that the current version of the cartridge tested (Lehigh Defense Xtreme Penetrator (XP) Ammunition in .380 ACP; mfr part #07380085S) is...

    380 Auto 90gr Xtreme Penetrator Ammunition
    https://www.lehighdefense.com/380-auto-90gr-xtreme-penetrator-ammunition
    SKU 07380090S
    Caliber / Cartridge 380 Auto
    Technology Xtreme Penetrator
    Weight (gr) 90
    Cartridge Overall Length(in) 0.950
    Velocity 950
    My guess is that the performance of the 90 gr bullet would be similar to the 85 gr bullet tested.

    Best regards,

    Bob
     
    NWG40 and Lucian_253 like this.
  12. G42-1952

    G42-1952 New Member

    9
    2
     
  13. G42-1952

    G42-1952 New Member

    9
    2
    carry same underwood.
     
  14. LostinTexas

    LostinTexas Well-Known Member

    I don't think a lot of folks think of 380 and barrier penetration in the same breath. There is a reason it isn't a service round. 13 inches of penetration is pretty impressive from a 380, 16 is even more so.
    380 is a belly gun, put in in their belly and fire. That is where most of it's claim to fame comes from, and it has a rather impressive one. I just don't want to need to get that close.
     
  15. rbbeers

    rbbeers Well-Known Member Lifetime Supporting Member

    3,653
    4,539
    That may be... but, given the subject bullet and the flavor of the discussion, it seems most appropriate (to me). :)

    Personally, I found the video Lucian posted to be very enlightening. :D

    Best regards,

    Bob
     
  16. Argee

    Argee New Member

    10
    8
    I'm a huge advocate of ARX ammo. It gives the best of both worlds. Adequate penetration and acceptable expansion. Its a lightweight bullet by design. The lighter grain equates into higher velocity. Its higher velocity equates to a substantial wound cavity comparable to expansion from a heavier bullet. It does all this via hydraulic cavitation which is basically the same principle that the hollow point works on. The downside of a hollow point is short barrels equal slow velocity which in turn equate to minimal to zero expansion of hollow point bullets... factor in the clothing factor which clogs the hollow point you may just as well shoot ball ammo. The ARX round is the game changer. By design the non expanding fluted bullet which is approximately 50% lighter than its lead HP counterpart has an increased velocity for penetration. The fluted end of the spinning projectile, which is pretty much barrier blind, creates extreme cavitation when it enters fluidous material such as the body cavity. That cavitation equates to an expansion the same or better than the equivalent HP working at its maximum capacity. The recoil is much less giving you the ability to do follow up shots quickly as you can get back on target faster.

    The only problem is finding the ammo in these crazy times.
     
  17. rbbeers

    rbbeers Well-Known Member Lifetime Supporting Member

    3,653
    4,539
    Maybe not... ;) :rolleyes: :D





    Best regards,

    Bob
     
    NWG40 and Lucian_253 like this.
  18. Lucian_253

    Lucian_253 Well-Known Member Supporter

  19. Lucian_253

    Lucian_253 Well-Known Member Supporter



    Only video I could find with the 65gr Underwood Xtreme defender .380 I currently have in my mags.
     
    NWG40 and rbbeers like this.
  20. rbbeers

    rbbeers Well-Known Member Lifetime Supporting Member

    3,653
    4,539
    Very interesting videos, Lucian. Thanks! :)

    Best regards,

    Bob
     
    NWG40 and Lucian_253 like this.