Keeping non 5.56 ammo out of my 5.56 AR

Discussion in 'Rifle Country' started by EMT40SW, Sep 29, 2022.

  1. Robert

    Robert Administrator Staff Member

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    I have 2 ARs, 5.56x45 and 7.62x51. I'm not worried. But I know lot of folks with this issue. Different colored or marked mags seems to be the cheapest and easiest.
     
  2. Lo-Profile

    Lo-Profile Member

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    I have AR's in 4 different calibers.
    I color code the magazines with tape on the magazine and on the dust covers
    5.56, Black (regular magazines)
    300 BO, FDE (Magpul)
    350 legend, Green
    450 Bushmaster, Blue
     
  3. highlander 5

    highlander 5 Member

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    I have my 5.56 and 300 blk in MTM 100 rd boxes labeled with caliber.
     
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  4. TonyAngel

    TonyAngel Member

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    Paint pen.
     
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  5. NR53

    NR53 Member

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    All uppers and magazines get marked(as to caliber) with scotch tape and a sharpie
     
  6. browneu

    browneu Member

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    I have different colored grips for my AR's black for .556 and FDE for 300 blackout. Plus I label my magazines for 300 blackout. No label is .556. I even label my magazine according to super sonic and sub sonic. Just my way of staying organized.
     
  7. JeeperCreeper

    JeeperCreeper Member

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    My grendel and bushmaster mags and ammo use special mags so it's not really a concern.

    I use orange tape and sharpie on my 300blk mags so anyone, not even me, can tell that they aren't normal.

    I also keep all my ammo in labeled ammo cans so I don't mix anything up. Never loose rounds.

    I almost never bring both a 300blk and 5.56 to the range at the same time and I empty my range bag after ever trip.
     
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  8. CapnMac

    CapnMac Member

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    There are enough colors of "bits" out there that a person could match them caliber by caliber.
    So, a person could build a blue AR for a given caliber, and a red one for yet another.
    AR, in large or small frame offer so many possibilities as to make this as easy or as difficult as a person could desire.
     
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  9. db_tanker

    db_tanker Member

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    I only use 10 round mags in my 30 blackout. No worries here.
     
  10. kje54

    kje54 Member

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    I have 5.56 and 7.62x39 in rifle ammo so I don't worry about loading the wrong ones in a mag. I keep all my different ammo in marked (plastic) ammo boxes I picked up cheap at Harbor Freight and a couple of old metal surplus cans.
     
  11. Driftertank

    Driftertank Member

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    Pretty sure Grendel rounds shouldn't seat into a 5.56 bolt face (Rim diameter .440" vs .378" nominal) so in theory there's no way the firing pin would reach the primer if someone chambered a 6.5 in a 5.56...

    In practice, not 100% sure, but I wouldn't lose sleep about it.

    As for .300, presumably the bullet width wouldn't allow the case to headspace into the chamber, so the BCG would be out of battery where the bolt stops, and in any lower that's close to in-spec, the hammer will hit the BCG shroud before the firing pin. If your bullet is seated deep enough that it won't hit the chamber shoulder before the bolt is in battery, I suppose that could be an issue....but I can't say for sure, as I haven't played with loading .300BLK.

    I mean, if it's a major concern, just make sure you only have one out of it's case at a time, keep the ammo separate and clear any loaded mags before switching rifles.
     
  12. wesmonster

    wesmonster Member

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    I tag or color code all my AR variant mags (.300bo, 6.5Grendel, 7.62x39 and 5.45x39). Just cause a mag is stamped with a caliber isn't enought, color or LARGE fonts are easy to see in a dark range bag.
    For 5.56 I run translucent Lancers, so I can always take a quick glance if I'm not 100% sure.
    I also don't bring 5.56 and .300bo ARs out at the same time, one or the other, and each caliber stores in a different ammo can.
     
  13. someguy2800

    someguy2800 Member

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    The force of the bolt running into the case is enough to push the bullet back into the case until the bolt closes. At that point the cartridge head spaced off the bullet and will fire.
     
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  14. shuvelrider

    shuvelrider Member

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    Buy a FAL, you wont confuse mags anymore! :)
     
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  15. Riomouse911

    Riomouse911 Member

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    Like having one powder, bullet and load at once when sitting at the reloading bench, just put one type of ammo and one gun out at a time if you have others shooting your stuff.

    I learned this when a neophyte buddy loaded and fired his .45 Colt revolver after grabbing .44 Magnum loads out of the wrong ammo can. If it wasn’t an old model Vaquero that he was shooting, it could have been catastrophic. :what:

    Stay safe.
     
    Last edited: Oct 4, 2022
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  16. JDGray

    JDGray Member

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    You could always look at the bbl, only take the correct ammo to the range.
     
  17. Bcwitt

    Bcwitt Member

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    A 556 will go bang in a x39 chamber, but thats not a disaster either.
     
  18. eddiememphis

    eddiememphis Member

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    Unless you build two exactly identical rifles, it should be easy to identify them.

    If you are you worried someone about mixing up your rifles and blowing them up you should limit access to non-idiots.
     
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  19. JShirley

    JShirley Administrator Staff Member

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    Byron had a habit of buying multiple identical handguns. Sometimes they would be identical in every respect, and sometimes they would be the same except for caliber. He became somewhat more cautious after slapping in a mag of 10 mm in his Dan Wesson 1911 .45, and touching off a round. Fortunately, there was no damage or injury.
     
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  20. gotboostvr

    gotboostvr Member

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    Unless you end up with both inch and metric mags somehow!

    Or worse, you end up like my buddies Century FN FAL. It wouldn't run with either inch or metric. Just the one mag it came with. 5-6 of both types wouldn't run more than 1-2 causes cartridges at a time if at all. That one mag it came with ran pretty well though. But it somehow didn't match up with either inch or metric. Just Century being Century I guess.
     
  21. Varminterror

    Varminterror Member

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    In safety process design, we have two types of safeguards - physical/mechanical and procedural. Because procedural safeguards are ALWAYS vulnerable to human error - aka, ignoring, forgetting, or failing the procedure - procedural safeguards are never considered “Full Value ISL’s,” independent safety layers, for any risk identified as class C or higher, meaning an incident could result in significant injury or death. Such, procedural safeguards always require additional independent safety layers to create a full value safeguard. Also pointing out here, most A and B class risks require MULTIPLE ISL’s, not just one.

    So given that paradigm, we could never rely upon any procedure - such as marking magazines, ammo, or uppers, or separating/segregating ammo, or only loaning out one rifle and matching ammo at a time, etc. Any procedure like this is not infallible.

    For example - despite marking magazines, an unwitting shooter might not realize the meaning of the markings (different sized mags or colors), or the markings may fail (bands slipping off or breaking), or a person still might load the wrong ammo into the magazines, or simply grab the wrong rifle, or assemble a non-5.56 upper onto a 5.56 marked lower, or a person might put ammo into the wrong box, or put a box of factory ammo on the wrong stack or shelf, or… or… or…

    However…

    Physical/mechanical safeguards DO constitute full value ISL’s, so mechanical safeguards are far more reliable than procedural - human dependent - safeguards. We like to pretend in firearms world that our procedural 3 rules of gun safety are the highest safeguards, but statistically and factually, mechanical safeguards always promote greater safety than procedures. Bluntly, you are more apt to forget to activate a mechanical safety on a rifle, or inadvertently deactivate the safety than the mechanical safety is apt to fail - AND - good PSM programs require methods to regularly confirm function of safeguards.

    But physical fit is a mechanism which cannot fail - so quite literally, owning the 300blk is the only real risk in this scenario. There is no other combination of cartridges between which the larger bullet diameter cartridge will fit into the chamber of a smaller bore cartridge. 6.8 SPC, 6.5 Grendel, 204 Ruger, 17 Rem, 20 Pract, 6 ARC, 223/5.56, 458socom, 450 bushy, 350 Legend, 224 Valkyrie, 22 Nosler, 25-45 sharps, 7.62x39… all of these have sufficient interference in cartridge dimensions such none of the larger bore cartridge ammunition will fit into a smaller bore cartridge chamber. For the few which CAN chamber into eachother such as 17 Rem being fired in a 223/5.56 rifle or 6 ARC in a 6.5 Grendel rifle, the under-sized bullet will rattle down the bore, with no greater severity of consequence. The 300blk is the only larger bore cartridge which is sufficiently short to successfully chamber into a smaller bore, 223/5.56 chamber, causing a bore obstruction and potential catastrophic failure in a single shot.

    So mechanically, no combination of cartridges and rifle can present a significant risk if you do not own a 300 blackout. If you DO own a Blackout, then there’s really nothing beyond fallible procedures which can prevent a Kaboom, which then requires at least two procedural confirmations to promote a single layer of safeguarding.
     
    Last edited: Oct 5, 2022
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  22. gotboostvr

    gotboostvr Member

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    This whole thing is partly why I'm on the fence for a 300blk.

    I can go 7.62x39 or 350L with almost as much ease and similar performance, and a much higher degree of safety. If it was just me, I would be very comfortable with a 300blk, but between the wife and kids, there's a fair chance for a mix up.
     
  23. Skylerbone

    Skylerbone Member

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    I physically checked a single round of 350L two nights ago when discussing this thread with a friend. Pulled the takedown pin, removed the BCG, and tried stuffing a cartridge in- no go. I had not considered the dissimilar other chamberings before then and happy to now read above that there is only 1 which creates a significant risk.
     
  24. shuvelrider

    shuvelrider Member

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    It just comes down the "headspace and timing" of the operator, keep your gear basic and simple to what works for ya.
     
  25. highlander 5

    highlander 5 Member

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    There is one other thing you could do to prevent misidentification,Starline has nickel plated brass in 223. I've some Remington nickel plated 223 brass in my stash.
     
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