Best 5.56 "Duty" Round

I am looking to build a serious duty rifle, I am not going to cheap out this time, I have been saving and am prepared to pay a premium.

Not considering price, what is the best 5.56 duty round with a muzzle velocity above 3000fps+

  1. 4 weeks ago
    Anonymous

    M193

  2. 4 weeks ago
    Anonymous

    Get .308

  3. 4 weeks ago
    Anonymous

    220 swift

  4. 4 weeks ago
    Anonymous

    Why are you worried about the muzzle velocity being over 3k?

    • 4 weeks ago
      Anonymous

      This, who the fuck cares? Temporary cavitation damage is dependent on multiple variables besides velocity.

      >Tissue Damage, Range
      Black Hills 77 gr TMK

      >Barrier Blind
      Gold Dot
      62 gr TBBC or 64 gr BSB if you’re super autistic about barrier performance
      50 gr Black Hills TSX or 70 gr TSX if you’re super autistic about finding factory 5.56 pressure rounds

      >Barrier Penetration
      M855A1

      >AP
      Just about all 5.56 rounds kinda suck at this but M995 (or the even rare AP4) are basically the only ones that have serious armor piercing capability.

      • 4 weeks ago
        Anonymous

        newfag here

        what other factors determine the temp wound cavity, from what ive heard people only really care about velocity when it comes to that

        • 4 weeks ago
          Anonymous

          Look you have to account for all the lanklets. All those rounds that anon posted have shitty performance against lanklets and overall performance. They all just ice pick with like a 30% to tumble or fragment depending on the boolet.
          Hunting rounds are the best munitions because even if you get hit, all the energy is being dumped on impact and not just that due to the enormous pressure entering in the body you'll get internal hemorrhaging or worst ruptured organs.

          • 4 weeks ago
            Anonymous

            >All those rounds that anon posted have shitty performance against lanklets and overall performance. They all just ice pick with like a 30% to tumble or fragment depending on the boolet.
            You have no idea what the fuck you are talking about.

          • 4 weeks ago
            Anonymous

            ???

            Every single bullet posted in

            This, who the fuck cares? Temporary cavitation damage is dependent on multiple variables besides velocity.

            >Tissue Damage, Range
            Black Hills 77 gr TMK

            >Barrier Blind
            Gold Dot
            62 gr TBBC or 64 gr BSB if you’re super autistic about barrier performance
            50 gr Black Hills TSX or 70 gr TSX if you’re super autistic about finding factory 5.56 pressure rounds

            >Barrier Penetration
            M855A1

            >AP
            Just about all 5.56 rounds kinda suck at this but M995 (or the even rare AP4) are basically the only ones that have serious armor piercing capability.

            besides AP3/4 (because terminal performance is not what it is optimized for, at all) is a non-yaw dependent round that begins expanding and/or fragmenting in less than an inch.

            70 gr TSX is explicitly advertised for hunting, 77 gr TMK is one of the most proven .223 medium game bullets around, and there are no shortage of documented deer kills with Gold Dot/Fusion.

            • 4 weeks ago
              Anonymous

              >77 gr TMK is one of the most proven .223 medium game bullets around,
              A simple search will show tons of examples on deer and hogs. Even dozens of elk taken with it. Someone’s used it for moose also. It’s really an amazing bullet

          • 4 weeks ago
            Anonymous

            You dumb as fuck, triple shocks are solid copper hollow points, and SMK,s are soft as shit and will pancake at basically any speed.

          • 4 weeks ago
            Anonymous

            >. All those rounds that anon posted have shitty performance against lanklets and overall performance. They all just ice pick with like a 30% to tumble or fragment depending on the boolet.
            >Hunting rounds are the best munitions because even if you get hit, all the energy is being dumped on impact
            None of this is true

          • 4 weeks ago
            Anonymous

            >you have to account for all the lanklets. All those rounds that anon posted have shitty performance against lanklets
            62 grain from short unstabilized barrels is the only time this was an issue

        • 4 weeks ago
          Anonymous

          Frontal area
          Form factor (tissue drag coefficient, more or less)
          Fragmentation

          All of these make a significant difference.

          .308 bonded soft points do more damage than 5.56 bonded soft points at similar velocities. That’s frontal area.

          You can load up a .45-70 flat point bullet at 1600 FPS and get it to make a hole significantly bigger than itself. That’s form factor.

          Fragmenting M193 creates larger wounds than nonfragmenting M80 ball. 5.45 7n6 bullets cause very little temporary cavitation damage in many flexible tissues and organs. That’s fragmentation (and also form factor and frontal area, in a sense).

          • 4 weeks ago
            Anonymous

            Best answer, slept on tbh

          • 4 weeks ago
            Anonymous

            Fragmentation isn't increasing wounding from a temporary cavity, it sometimes can increase lethality, depending on when the fragmentation occurs, because now you have multiple crushing permanent wound channels, increasing hit probability of a major blood vessel.
            The problem with fragmentation is its random, and if it occurs to early, the pieces may under penetrate, making the projectile less effective.
            The idea that a rifle round needs to fragment to be effective is nearly 60 year old military dogma, dreamed up by the same types of retards who made all those shitty changes to the m16.
            A projectile, that states in 1 piece, and penetrates deeply will always be superior to a fragmenting bullet, if a bullet fragments deeply, then it can be good, but it's a coin toss.
            That being said, the heavier the projectile that fragments, the higher chance if those fragments penetrating deeper, and therefore more effective.

        • 4 weeks ago
          Anonymous

          Don't worry so much about temp cavity and velocity. Velocity is definitely your friend, but bullet construction is by far the most important. M193 is ok, but the tumbling effect isn't consistent, and it becomes dramatically less effective with shorter barrels or longer ranges. 77 grain OTM loads fragment and make big nasty wounds because of their thin jackets but that also makes their barrier blindness poor and they also can icepick at slow velocities. IMO 62 grain bonded bullets are ideal. Anons above have mentioned some good bonded loads like federal TBBC and speer gold dots but theyre expensive and hard to find. I run federal fusion MSR because its performance is almost identical to those loads but I can actually find it online/in stores and its only ~$1 a round (same price as OTMs). Loads with barnes bullets (like that black hills 50gr tsx) are great too but they're also pretty pricey and hard to find.

          • 4 weeks ago
            Anonymous

            Federal Fusion and Gold Dot are practically the same bullet design, in fact I think the 62 gr Federal Fusion MSR load literally just uses a 62 gr Gold Dot projectile.

            Federal and Speer are both owned by the same parent company so it makes sense (through cross-company loading also exists, 64 gr Nosler BSB for example is usually loaded by Winchester).

            >77 grain OTM loads fragment and make big nasty wounds because of their thin jackets but that also makes their barrier blindness poor and they also can icepick at slow velocities.
            This is potentially true for stuff like 77 gr SMK and 75 gr Hornady TAP T1, but 77 gr TMK is an expansion-dependent design that mushrooms down to likely <1600 FPS. It's still not barrier blind but probably does pretty much fine in the drywall and plywood FBI-tests and semi-okayish in the car door simulation, leaving auto glass as the only barrier test where it likely just outright sucks.

            • 4 weeks ago
              Anonymous

              Yeah actually looking at gold dots online I think you're right. The ogive and tip look exactly the same as MSR. Neat, I didn't realize. As for expansion, bonded bullets also have a pretty low threshold velocity for expansion, but since you're starting with a higher MV you should theoretically have longer range where the bullet will still expand. The matchkings might hold onto their velocity better due to the high BC but from a shorter barrel I think the 62 grainers would take the cake. What do you think?

              • 4 weeks ago
                Anonymous

                Expansion range of Gold Dots is good but probably not quite on the same level as 77 TMKs. To math it out:

                Black Hills 77 gr TMK has a muzzle velocity of around ~2350 FPS out of a 10.5" barrel, with a G7 BC of 0.202. We'll say a minimum expansion velocity of about 1550 FPS although I think it probably runs a little lower than that.

                About 425 yards expansion range.

                Loaded to 5.56 pressures, 62 gr Gold Dot might attain velocities of about 2650 FPS out of a 10.5" barrel, with a practical G1 BC of about 0.26 (Speer's listed numbers are reportedly...optimistic, also using G1 here as, if I recall correctly, it suits Gold Dot's shape better). Minimum expansion velocity appears to be about 1650 FPS, the tip may still deform a bit under that velocity but probably not enough to make the nose wider than the base of the bullet, so it wouldn't functionally increase diameter.

                Comes out to about 330 yards expansion range.

                Fusion MSR runs somewhat slower than a full power 5.56 loading, so probably closer to 300-ish yards.

                Nosler 70 gr Accubond might improve on that but there doesn't seem to be a lot of information available on that bullet.

                It's arguably of academic importance as 300+ yard shots aren't the primary application of bonded rounds out of a 10.5" 5.56, but for pure expansion range, I don't think you can beat TMKs (outside of perhaps Hornady's fairly similar ELD-M loadings, although 75 gr and up can't be loaded to mag length, and the penetration of the 73 gr ELDs and down tends to be pretty mediocre for defensive use, more so out of the common 16" barrels and longer).

              • 4 weeks ago
                Anonymous

                Man 425 yards of expansion range is nuts for a 10.5". Are you sure the expansion velocity for TMKs is that low? I think SMKs only expand down to like 18/1900.

              • 4 weeks ago
                Anonymous

                picrel from someone else on rokslide, it's allegedly the result of a 77 gr TMK 1515 FPS impact on an elk's neck. Not a very big wound, probably about the size of a modestly expanding 9mm JHP, but a lot better than a .22 icepick at least. That being said, it's possible that it didn't expand and instead just yawed (the left side of the hole in particular looks rather like the side profile of a bullet) and the person handling it accidentally tore the wound open wider either with his hands or his knife, hard to say for certain.

                This video is probably a more sure measure of 77 gr TMK's low velocity capabilities:

                ?t=181

                1650 FPS and somewhere around 0.4" expansion with 16-17 gr fragmentation, meaning it's probably comfortably over its minimum expansion threshold. 62 gr Gold Dot doesn't seem to expand as much at 1700 FPS and its minimum threshold is 50 FPS lower, so extrapolating from there, 77 gr TMK's minimum expansion threshold is probably more than 50 FPS below 1650 FPS.

                77 gr SMK has a frag velocity of about 2100-2200 FPS. Very accurate bullet with a high BC but its actual deformation range is surprisingly modest. It's also yaw dependent and, while relatively rare, can occasionally icepick even above its normal fragmentation velocity.

              • 4 weeks ago
                Anonymous

                damn didn't realize there was such a gulf in performance between the SMK and TMK, I always assumed they'd behave more or less the same. Expanding like that and still hitting ideal pen depth is impressive for what's basically almost handgun velocity. Thanks for sharing dude, this is why night k is so much better than day k.

              • 4 weeks ago
                Anonymous

                Best answer, slept on tbh

                Thanks, I'm glad that terminal ballistics info is appreciated. Too often these kinds of discussions devolve into slapfights and the same myths and "common wisdom" being repeated ad infinitum.

              • 4 weeks ago
                Anonymous

                >Thanks for sharing dude, this is why night k is so much better than day k.
                Kids are doing homework, euros are asleep, shills clocked off, real people are off work.

                Also threads tend to not move as fast so discussion can be had.

              • 4 weeks ago
                Anonymous

                Yes it is that low. The TMKs are fantastic. Regardless you have excellent expansion within the effective range or your rifle. That could be a 10.5” and be 200 or 300 max. Or a scoped 20” and 400-500 yards

        • 4 weeks ago
          Anonymous

          You're asking the wrong question.
          Temporary cavitation doesn't aid in lethality, or a rounds ability to quickly cause physical incapacition.
          The crushing path is all that matters, Temporary cavity at most causes minotlr bruising and lacerations to soft tissue for at max a few CM away from the permanent cavity, with the exception of liver and brain tissue.

      • 4 weeks ago
        Anonymous

        This is a good list. But if I could only have one id be mk318. Fragmenting tip, with a solid copper base for penetration, and extremely barrier blind. If I could have two if by mk262, and 62gr TSX loaded hot as shit.

      • 4 weeks ago
        Anonymous

        Temporary cavitation causes none, to extremely minor soft tissue damage, and is essentially a non-factor

        • 4 weeks ago
          Anonymous

          You're asking the wrong question.
          Temporary cavitation doesn't aid in lethality, or a rounds ability to quickly cause physical incapacition.
          The crushing path is all that matters, Temporary cavity at most causes minotlr bruising and lacerations to soft tissue for at max a few CM away from the permanent cavity, with the exception of liver and brain tissue.

          Then why do bonded .223 rounds make holes 1"+ inch across? It's not because of tissue crushing through direct contact, because the bullets don't expand to an inch in diameter. Is 230 gr HST more effective than a .308 TBBC because it expands wider and makes a larger crush cavity?

          Dr. Martin Fackler, who was one of the first people to argue that the role of temporary cavitation was overstated, later scaled back his position. His colleague, Dr. Roberts, notes that noticeable TSC damage from well-engineered .357 magnum bullets starts appearing at speeds as low as ~1600 FPS.

          Fragmentation isn't increasing wounding from a temporary cavity, it sometimes can increase lethality, depending on when the fragmentation occurs, because now you have multiple crushing permanent wound channels, increasing hit probability of a major blood vessel.
          The problem with fragmentation is its random, and if it occurs to early, the pieces may under penetrate, making the projectile less effective.
          The idea that a rifle round needs to fragment to be effective is nearly 60 year old military dogma, dreamed up by the same types of retards who made all those shitty changes to the m16.
          A projectile, that states in 1 piece, and penetrates deeply will always be superior to a fragmenting bullet, if a bullet fragments deeply, then it can be good, but it's a coin toss.
          That being said, the heavier the projectile that fragments, the higher chance if those fragments penetrating deeper, and therefore more effective.

          >Fragmentation isn't increasing wounding from a temporary cavity
          It absolutely does, if both effects are substantial enough. The fragmentation works synergistically with the TSC by weakening the structure of the surrounding tissue, allowing the temporary cavity pulp and rip the flesh apart. This has long been known by wound ballisticians, Fackler himself never disputed this and in fact was one of the first people to tout it as a wounding mechanism that substantially increased tissue destruction.

          >The problem with fragmentation is its random
          Like with what? With M193 fragmentation is somewhat variable though still extremely common. With M855A1 and 77 gr TMK it happens practically all the time above a specified velocity. I have tested multiple shots of TMK myself in calibrated gelatin.

          >60 year old military dogma
          No it's not, even after M193 started being used in Vietnam, it took a while before Dr. Fackler identified fragmentation as the cause of increased wounding compared to older bullets. Before that everyone thought yaw/tumbling was responsible, turns out pretty much every fucking spitzer bullet tumbles.

          • 4 weeks ago
            Anonymous

            To add on, I doubt it will stop that person from reiterating his "fragmentation and TSC don't matter for rifles" rhetoric, but here's some pictures and data just to illustrate what I'm talking about for everyone else.

            .45-70 bullet fired *backwards* (so no expansion), impact velocity likely ~1700 FPS because lol ballistic coefficient
            https://images.zeald.com/site/ballisticstudies/images/Resources/Terminal_Ballistics3.jpg
            https://images.zeald.com/site/ballisticstudies/images/Resources/Terminal_Ballistics4.jpg

            Lung wounding from .45 Colt FP Hardcast round at about 1300 FPS - again no expansion. Holes are not that big, but clearly still wider than the bullet.
            https://www.shootersforum.com/attachments/45coltlungs-jpg.10431/

            .223 55 gr TSX wounding, very modest by rifle standards, but still bigger than the expanded bullet.
            https://www.ballisticstudies.com/site/ballisticstudies/files/223%20Rem%2055%20gr%20TTSX%20PDF.pdf

            Dozens of recorded kills and wound photographs with 77 gr TMK here. Clearly a 77 gr .223 is not going to directly crush a gaping 4" wound, you couldn't flatten a bullet like that into a 4" wide circle even if you pounded it with a sledgehammer. Obviously there are wound mechanisms at play allowing it to inflict damage far beyond the margins of what it directly contacts.
            https://rokslide.com/forums/threads/223-for-bear-deer-elk-and-moose.130488/

            ^Also a couple of TSX, Gold Dot/Fusion, and ELD-M kills there as well.

            Here's what happens when you don't have appropriate shape and frontal area to cause consistent, severe temporary cavitation damage in spite of high velocity (5.45x39 7n6):
            https://web.archive.org/web/20090219104944/http://ammo.ar15.com/project/Fackler_Articles/ak74_wounding_potential.pdf
            Just look for M193 & .223 55 gr FMJ wounds when you take a bullet of similar velocity and size and add fragmentation into the mix. Grosskreutz's arm would be a decent starter.

            Hopefully that gets the point across.

      • 4 weeks ago
        Anonymous

        Good post

  5. 4 weeks ago
    Anonymous

    VMAX to vaporize limbs

  6. 4 weeks ago
    Anonymous

    5.5mm Velo-Dog

  7. 4 weeks ago
    Anonymous

    m855a1 is good and possible to get when it falls off a truck. You're going to pay a huge premium though, around $2 per round isn't crazy but you only need like 90 rounds, otherwise m193 is good. Not all m193 is made equal though

  8. 4 weeks ago
    Anonymous

    5.56NATO MK318 MOD 1 - 62 GRAIN

  9. 4 weeks ago
    Anonymous

    Anything from Black Hills, Mk262 and other high weight hpbts, Hornady TAP, anything with the Federal TBBC or SMK 77gr bullets. There are a few different FBI barrier blind loads that are supposed to be good too.

  10. 4 weeks ago
    Anonymous

    m193 with a 20" 1:14 twist barrel

    • 4 weeks ago
      Anonymous

      >m193 with a 20" 1:14 twist barrel
      Best answer

      5.56NATO MK318 MOD 1 - 62 GRAIN

      >5.56NATO MK318 MOD 1 - 62 GRAIN
      Second best answer

  11. 4 weeks ago
    Anonymous

    M193 or M995. Don't pussyfoot around in the middle.

  12. 4 weeks ago
    Anonymous

    black hills tsx 50 grn

  13. 4 weeks ago
    Anonymous

    At police shooting ranges, literally just m193.

    • 4 weeks ago
      Anonymous

      Do you mean at ranges that police shootings happen, or at the ranges you will shoot police? Either one is cool I’m just curious

      • 4 weeks ago
        Anonymous

        Silence, Fed

        • 4 weeks ago
          Anonymous

          Fuck off moron you can just say it was the 2nd option. The 2A exists to shoot those employed by the federal government.

  14. 4 weeks ago
    Anonymous

    quantity is its own quantity, so the cheapest (legit) M193 and/or M855 you can find

  15. 4 weeks ago
    Anonymous

    Help me out fellow 20"chads: why would anyone be a concerned about breaking a 3000 fps nuzzle velocity? Don't they know that's a the typical velocity for most forms of bulk ammo? Why wouldn't it be?

    • 4 weeks ago
      Anonymous

      AR500 busting.

  16. 4 weeks ago
    Anonymous

    SOFT POINTS
    (or otherwise expanding projectiles)

  17. 4 weeks ago
    Anonymous

    M193 out of a 20 inch barrel

  18. 4 weeks ago
    Anonymous

    Lake city m193 (WWB)

  19. 4 weeks ago
    Anonymous

    The answer is 62 grain barnes, or some 62gr bonded soft point like gold dots.

  20. 4 weeks ago
    Anonymous

    Does mk318 ever become actually available or should I give up on finding that? What's the best barrier blind round for an SBR?

    • 4 weeks ago
      Anonymous

      62gr gold dots you gay

      • 4 weeks ago
        Anonymous

        I mean gold dots are probably what I'm ending up with, yeah, but I wanna explore my options.

  21. 4 weeks ago
    Anonymous

    5.56NATO MK318 MOD 1 - 62 GRAIN

  22. 4 weeks ago
    Anonymous

    why are so many of the recommendations here completely unrealistic to purchase in bulk, literally half of everything here comes in a 20rd box at an upwards of $1 a round.

    • 4 weeks ago
      Anonymous

      Europoor?

      • 4 weeks ago
        Anonymous

        eurofags can't even buy ammo, much less in bulk

    • 4 weeks ago
      Anonymous

      just reload.

    • 4 weeks ago
      Anonymous

      OP literally says
      >Not considering price
      >am prepared to pay a premium

      You can buy a basic stash of premium ammo and then practice with whatever non-trash FMJ you find. If you run out of the good stuff then switch to your ball ammo and/or use whatever you've picked up off the ground.

      If you want cheaper options, standard 62 gr Fusion (slower than MSR) can be found online for less than a dollar per round. PPU 75 gr BTHP is a good performer at close range and their 55 gr SP is likely fine for most HD barrel lengths. As are an assortment of other 55 gr and 62/64 gr nonbonded JSPs, but you should do your research on the particular bullet.

      • 4 weeks ago
        Anonymous

        This. Or pick up reloading and load Hornady 75gr BTHPs with the cannelures. Not the best, but they are very good when you do price to performance.

  23. 4 weeks ago
    Anonymous

    55gr VMAX. Had to deal with the sucking chest wound squirting blood when I would accidentally compress the ribs. Lungs were good and paste. Hopefully I don't have rabies. Some blood got in my eyes.

  24. 4 weeks ago
    Anonymous

    Sierra 77gr TMKs are the best in terms of effect on target and long range trajectory. If you reload (which I’m thinking you don’t), Hornady 75gr BTHPs perform very similarly for a lot less

  25. 4 weeks ago
    Anonymous

    22-250. any bullet weight. If you're obsessed with the need to sneed you can push standard 55 grain 5.56 rounds 4000+ fps. Ignore barrel wear and long term accuracy effects from it you wanted speed didn't ya?

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