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Thread: 5.56 Fragmentation Effect Range

  1. #11
    New Member schüler's Avatar
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    Quote Originally Posted by john c View Post
    Thanks to each of you for the replies.

    The reason I asked is that, for patrol use, my agency issues Federal Green Tip 62 grain ammo. I think this is M855 equivalent? For the few shootings we've had with it, it works. We're running 16 inch barreled carbines, but only for a small subset of officers. We're in the process of changing to a bonded round, and I was just wondering how the envelope changes.

    Basically, for premium, bonded core rounds, how far out will they expand reliably, as a rule of thumb?
    @DanM @HCM @Gio Thank you for clarifying the wounding mechanism of premium rounds. I hadn't put that together, though it makes sense.
    @schüler Thanks for the pointer. I hadn't seen that.
    Paul Howe has specifically mentioned M855 as yet another reason why shot placement is always King. If you haven't seen it yet, here's a DocGKR 2008 presentation that touches on some of the variables.

    ATK used to (or still does?) hold "Wound Ballistic Workshops" at hosting agencies where they'd set up gel and barriers to demonstrate their newer ammunition vs. host agency's current issue ammo. Not the best controlled environment due to field conditions of varying gel temp, barrier angles not exact, etc. What appealed to me was the cumulative consistency of ammo performance over those varying conditions. They had some WBW info on their website but a lot more available if you asked.

    As DocGKR says... we have good ammo today and terminal ballistics vary from shot to shot. Individual shooter performance is the real deciding factor and that's where our time needs to be spent.

  2. #12
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    Quote Originally Posted by schüler View Post
    As DocGKR says... we have good ammo today and terminal ballistics vary from shot to shot. Individual shooter performance is the real deciding factor and that's where our time needs to be spent.
    I get what you're saying, but this is somewhat of a pet peeve of mine. Make sure your equipment is as good as it possibly can be, while simultaneously working on individual shooter performance. All the shooting skill does you no good if your rounds won't get through the intermediate barrier and penetrate far enough to stop the threat.

  3. #13
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    Quote Originally Posted by Duelist View Post
    5%?! Wow. Well, actually, that’s exactly what it is - a CBP friend gave me 3 or 4 boxes a few years ago.

    I am not carrying it around, I’m just an OEF/OIF vet who keeps an AR around because it seems weird not to have one. I’ll stick with this stuff until I get my hands on something else.
    If it is the old USBP duty ammo (sounds like it) it is not bonded.

  4. #14
    New Member schüler's Avatar
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    CORRECTION ON Win RA223R2 auto glass performance

    Quote Originally Posted by Duelist View Post
    5%?! Wow. Well, actually, that’s exactly what it is - a CBP friend gave me 3 or 4 boxes a few years ago.

    I am not carrying it around, I’m just an OEF/OIF vet who keeps an AR around because it seems weird not to have one. I’ll stick with this stuff until I get my hands on something else.
    Duelist, I apologize, I have a correction to make. Retained weight after passing through auto glass was around 13%, penetration was 5". I made a mistake. I found my old policy recommendation and here's a table I made:

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  5. #15
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    Quote Originally Posted by schüler View Post
    Duelist, I apologize, I have a correction to make. Retained weight after passing through auto glass was around 13%, penetration was 5". I made a mistake. I found my old policy recommendation and here's a table I made:

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    That’s cool. I know there’s a lot of guys who take what barrier blind ammo they use very seriously b/c you’re using the AR carbine as a patrol rifle. When I carried one as part of my job, i just carried the same M855 green tip everybody else in the Army did, so after I got out and built my 16” KISS lightweight carbine, my CBP friend gave me a few boxes of their duty ammo (I live in southern AZ), and I figured I was set for a while. And really, I probably am b/c this rifle gets trigger time a few weekends of the year, but mostly just sits at the front of my safe with a magazine of that ammo in condition 3, next to a 20g with a tube full of buck. And really, that’s about as much work as it’s likely to get. I hunt with shotguns and longer-range, more powerful bolt actions, carry a handgun every day, but the AR is mostly nostalgia and “just-in-case”.

  6. #16
    Site Supporter DocGKR's Avatar
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    For a 5.56 mm FMJ bullet to "fragment", it must first yaw, then hyper-expand, and finally it typically fractures at the cannelure.

    Win 64 gr RA223R2 was great ammo................in 1990. We have come a long way since then. Do officers still patrol in 1990 Caprice Classics? M855 is one of the WORST choices for a duty load.

    Going with a barrier blind load that meets the "8 Point of Light" espoused by former SSA Buford Boone of the FBI BRF is likely the best option for most defensive shooting needs.

    https://pistol-forum.com/showthread....-mm-Duty-Loads
    Last edited by DocGKR; 06-25-2018 at 02:32 PM.
    Facts matter...Feelings Can Lie

  7. #17
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    Our issued round is the Winchester Ranger 64 gr bonded load (RA556B).

    We have hosted 4 ballistic workshops since fielding this loading. Every time that we have tested it, the performance has been consistent. This load is also on the state contract for my state and the contract price per case is competitive with other duty loads.

    In today’s environment, the idea of using M855 green tip ammunition as a duty round is hard to comprehend. Even the US Army and Marine Corps have dumped M855 as an issuer duty round
    Last edited by Beat Trash; 06-25-2018 at 02:13 PM.

  8. #18
    Quote Originally Posted by john c View Post
    I was reading that M855 62 gr 5.56 ammo will fragment upon hitting flesh out to 125m from a 20 inch barrel, but only 85 yards from a 14.5 inch barrel. Fragmentation is one of the main wounding characteristics of the 5.56 cartridge.

    I have two questions:

    1) How much of a difference does fragmentation make for overall effect on target? Basically, if a target hit at 50 yards and full fragmentation is full performance, how much different would the effect on the same target be at 300 with no fragmentation?

    2) I see that M193 55 gr bullets add 5 yards or so to the fragmentation effect distance (130m from a 20 inch barrel, and 90 yards from a 14.5 inch barrel). What are the effective ranges for other bullets types and weights? I see that Hornady TAP is highly regarded. How about 45 grain bullets?
    It makes a huge difference. 5.56 when it just travels point forward, doesnt do much more than a .22 mag. When a M855 or M193 bullet fragments, the results in tissue are...dramatic. The problem with M855 is that it doesnt always fragment, or fragment at the right depth and its not just based on velocity. This makes it a poor duty load for any situation. Id focus on getting a good bonded SP or heavy OTM instead of what the fragmentation range of the bullet is.
    Last edited by vicious_cb; 06-26-2018 at 08:37 PM.

  9. #19
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    Our duty load. This usually gets a lot of laughs when I post this.

    Our boxes used to have little prairie dog images on it. We keep duty rounds for a decade so they may have changed the box since then.

    Regards.

  10. #20
    Site Supporter DocGKR's Avatar
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    Uh....I hope your admin realizes their choice is NOT within the standards for the profession and could set them up for significant liability should something not go well....
    Facts matter...Feelings Can Lie

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