Should all AR15s be 20 inch AR15s

There are 20 inch AR builds, and there are wrong AR builds. Discuss.

250 Piece Survival Gear First Aid Kit

LifeStraw Water Filter for Hiking and Preparedness

250 Piece Survival Gear First Aid Kit

  1. 2 years ago
    Anonymous

    20" is a good length. I agree OP

  2. 2 years ago
    BigC

    tired of 20 inch ar gays spamming this board with false info

    • 2 years ago
      Anonymous

      Clean your room BUCKO

      Mk.12 is the best, but the M16 DMR can be given to anyone anywhere

      They cleared houses with bolt action rifles in WWII

      20" is a good length. I agree OP

      150 IQ poster

      • 2 years ago
        Anonymous

        You've never taken a PhD level physics class. Give me a break

  3. 2 years ago
    Anonymous

    Mk.12 is the best, but the M16 DMR can be given to anyone anywhere

  4. 2 years ago
    Anonymous

    >small pp thread

  5. 2 years ago
    Anonymous

    18" is best "

  6. 2 years ago
    Anonymous

    isnt the M16 SDMR just the standard issue M16A4 in the Marines? Is the M16 SDMR an army thing?

    • 2 years ago
      Anonymous

      no

      • 2 years ago
        Anonymous

        well what's different
        >HHHPH

  7. 2 years ago
    Anonymous

    sorry CHUD, best length coming through

    • 2 years ago
      Anonymous

      it's too meaty for me. it's built so that even crayon eaters cant break it

    • 2 years ago
      Anonymous

      >Subverted National Defense: The Picture

  8. 2 years ago
    Anonymous

    reminder that you can just have multiple uppers and you dont have to stick with one barrel length

    • 2 years ago
      Anonymous

      >poopaloo pops off
      >load up kit
      >prepare my 20" ar with collapsible stock
      >meet up with pals
      >see kevin with 2 backpacks
      >one for the kit and one to carry his multiple uppers with different barrel lengths to cover all applications
      >cant take him into any of those applications because he fumbles around and makes a shit ton of noise
      >ambushes and the element of surprise are gone when he's involved

      • 2 years ago
        Anonymous

        >Kevin weighs almost 350 lbs
        >Kevin is also rrans btw

  9. 2 years ago
    Anonymous

    suppressors are just too good to go without. the flash reduction, noise reduction, and comfort shooting especially indoors.

    therefore, 14.5 is the best barrel length, because it basically gives you a 20" AR.

    • 2 years ago
      Anonymous

      Does that added length from the silencer increase muzzle velocity?

      • 2 years ago
        Anonymous

        No

      • 2 years ago
        Anonymous

        t. Has no idea how a suppressor actually works

        A suppressor is a metal tube with chambers that capture gases from the escaping projectile. They aren't extra barrel length. They are more likely to slow the projectile than accelerate it.

        • 2 years ago
          Anonymous

          No

          Iirc in real world testing a suppressor will increase muzzle velocity but not by a significant amount, definitely not enough to make up the difference between between 14.5 and 20" and thus, the M16 prevails.

          • 2 years ago
            Anonymous

            I never understood the 700-950 RPM. Is it referring to different barrel length fire rates, or is it actually completely randomized between those values?

            • 2 years ago
              Anonymous

              As the gun heats up the gas tube will expand, letting more gas through and causing the rifle to cycle more quickly

        • 2 years ago
          Anonymous

          t. doesn't know Socratic method. Or sarcasm.

      • 2 years ago
        Anonymous

        not enough to matter

      • 2 years ago
        Anonymous

        If all you care about is muzzle velocity, why handicap yourself with a 20" barrel? Why not 22" or 24" or even longer?

        • 2 years ago
          Anonymous

          do you know of any 24" pencil barrels? serious question

          • 2 years ago
            Anonymous

            No, because 24" barrels are mostly targeted to varminters who don't care about weight and do care about how fast their barrel warms up, but ADCO (or equivalent) will happily lathe your barrel down to whatever profile you want for a reasonable price.

  10. 2 years ago
    Anonymous

    There should only be 15" AR-15's

  11. 2 years ago
    Anonymous

    20 and 10.3 are the only acceptable barrel lengths

    • 2 years ago
      Anonymous

      Interesting take. I live in cornfield country, I made this thread cuz I’m thinking of upgrading my go to rifle from a 14.5 with a 1-6x LPVO to a 20” with a 1-8x. Ive already got everything ordered, can’t wait to see how it looks slapped together

  12. 2 years ago
    Anonymous

    Wow, I had no idea my moron AR build actually had a name... Special Purpose Rifle it is!

    • 2 years ago
      Anonymous

      That's sex

    • 2 years ago
      Anonymous

      How do you like that acog?

    • 2 years ago
      Anonymous

      >putting a nice scope on ruger dogshit
      lol, lmao

  13. 2 years ago
    Anonymous

    If its 5.56 yes, but I hope we switch trains and one day we upgrade to a more ballistically efficient caliber

  14. 2 years ago
    Anonymous

    Thats not how u say 18in barrel. Just got my upper today with MOE buttstock. To go with 11.5 upper with brace.

    • 2 years ago
      Anonymous

      Why would I want none of the velocity of 20” and none of the maneuverability of 14.5/16? Genuinely asking

      • 2 years ago
        Anonymous

        Still close to velocity as 20in while more velocity then 16in. Still manuverable as a 16in, wtf are you talkin bout?? I was actually ordeing a 20in upper and a lower but guess what i sent it back and bought 18in upper last minute

        • 2 years ago
          Anonymous

          Also pic related for 55gr

          • 2 years ago
            Anonymous

            That chart is way off. M193 out of a 20" is about 3180-3220, depending on the ammo. Out of a 16", you are getting about 3050 fps. It may not seem like much, but that extra 150 fps means the M193 from the 20" still has bullet upset to almost 200 yards, whereas the 16" only has bullet upset to about 125 yards. Not to mention a flatter trajectory to mid ranges, such as 250-400 yards. And because it's going faster at range, it's bucking the wind a bit better, too.

            • 2 years ago
              Anonymous

              >that chart, which was generated with a chronograph and a hacksaw, is way off
              >these numbers I pulled out of my ass are way more accurate

            • 2 years ago
              Anonymous

              most target load .223 you're shooting is probably around 3050 yes but m193's spec is literally 3250fps out of a 20" barrel

            • 2 years ago
              Anonymous

              You're not getting a 150 fps difference between 20" and 16" At most it will be 120, and with most other loads it's actually closer to 100 fps difference. Basically indistinguishable.

              • 2 years ago
                Anonymous

                with as fast as 5.56 decelerates every inch of barrel you cut substantially reduces its effective range, esp comparing to other rifle cartridges

              • 2 years ago
                Anonymous

                1. So why 20" instead of 22", 24", &c.?
                2. Looking at the procurement decisions made by LE/mil orgs that actually shoot people regularly, 14.5"–16" seems like it's good enough for most realistic use cases—do you disagree? If so, why?

              • 2 years ago
                Anonymous

                because

                most target load .223 you're shooting is probably around 3050 yes but m193's spec is literally 3250fps out of a 20" barrel

                u fricking dummy
                5.56 was designed for a 20" barrel, with a target velocity of 3250fps. quit playing the moron, you know better

              • 2 years ago
                Anonymous

                >muh le/mil
                they're fricking morons. listen to the guy who made the rifle, not the ones who sabotaged it

              • 2 years ago
                Anonymous

                >listen to the guy who had to spec out a rifle to defeat a steel helmet at 600 yards, not the guys actually using the rifle in real life—not some bureaucrat's fantasy of what combat is like
                yeah

              • 2 years ago
                Anonymous

                if it wasn't for him your dumb ass would be carrying around a 15lb hunk of wood and 20lbs of ammo for it still

      • 2 years ago
        Anonymous

        I wouldn't bother arguing with someone that takes a screenshot of a picture they already have in their gallery. Especially if the picture is that shit.

        • 2 years ago
          Anonymous

          Frick off cousin frickin cracka, da jpg is too big to upload.

      • 2 years ago
        Anonymous

        Pretty close to 20'' velocity and has nice smooth rifle length gas.
        The only reason they picked 18 instead of 20 was because the logistics people thought having two kinds of 20'' barrels would be too confusing.

    • 2 years ago
      Anonymous

      Nice I just got the like 2 weeks ago.

    • 2 years ago
      Anonymous

      Wait I'm a moron, you said buttstock.

  15. 2 years ago
    Anonymous

    That is not true, OP. There are also 22" and 24" options to consider once you start chambering for better rounds.

  16. 2 years ago
    Anonymous

    >not using a 2" barrel with a 14" pinned and welded muzzle device

  17. 2 years ago
    Anonymous

    I like my SDMR replica. It's nice.
    >Not just because it's the cheapest and easiest replica to make

  18. 2 years ago
    Anonymous

    frick off old frick

  19. 2 years ago
    Anonymous

    Rate the level of autism on my build, wanted a GPR and got an 18 in BCM stainless upper which is normally 750ish but my LGS had one for just under 600. Really only got it for the price, knowing more now i would have just spent the extra money for a 14.5 CHF off of BCM’s website. Still happy with the gun for a first AR and just a hair under 2 MOA at 100 yards with this new microprism scope.

    >Inb4 needs a light
    Yeah yeah im poor and a surefire M600U is 400 bucks

    • 2 years ago
      Anonymous

      >Yeah yeah im poor and a surefire M600U is 400 bucks
      X300T Is closer to 300 and has most of the same capability.

  20. 2 years ago
    Anonymous

    Not all ARs are 5.56. Some cartridges maximize at different barrel lengths. You're generally correct, but specifically wrong.

  21. 2 years ago
    Anonymous

    Holy fricking shit it's not that complicated. Set a maximum range for the rifle and pick the shortest length that gives you supersonic performance at the maximum distance with 77gr projectiles. If you intend to shoot the gun beyond 500y then get a 20" barrel. If it's a 300y and in gun then a 12.5" is sufficient. If it's a 100y and in gun get a 10.5".
    >how far away do I need to deliver a supersonic projectile?
    This is the question to ask when evaluating barrel length. If we're talking hunting rifles then the question becomes
    >How far away do I need to deliver a projectile in excess of 2200fps?
    It's not that difficult and can be figured out with some really simple calculations.

  22. 2 years ago
    Anonymous

    pencil 20" weigh as much as 12-14" "govt" profiles, only other argument is maneuverability which is a fricking joke, there are plenty vidoes out there of hajis using m16s from cars without an issue

  23. 2 years ago
    Anonymous

    I don't need it, but I want that SAM-R

    • 2 years ago
      Anonymous

      That SAM-R is wrong. They have stainless Compass Lake barrels, not phosphated A4 barrels.

      Me too, but the FSP is unobtanium.

      Quad rails are an abomination

      t. Male with feminine baby hands.

  24. 2 years ago
    Anonymous

    Anything below 24" wont be able to penetrate level 4 plates unless you have rare ammunition you wont have easy access to, 24 inches is actually the bare minimum.

  25. 2 years ago
    Anonymous

    20” A4 for the win

  26. 2 years ago
    Anonymous

    A4 brethren unite. We will grow tired of winning but we have no choice but to keep on.

    • 2 years ago
      Anonymous

      >a2 barrel
      please go

  27. 2 years ago
    Anonymous

    So a buddy of mine was in the marines for 20 years, I think it was between 1998 to 2018 or so.
    He's always wanted an AR but is too cheap to get one.
    What build would be close to what he might have used the most if I were to get him one as a gift?

    • 2 years ago
      Anonymous

      any generic A4gery
      Colt, Aero, whatever—a Marine isn't going to notice the difference anyway

  28. 2 years ago
    Anonymous

    Quad rails are an abomination

Your email address will not be published. Required fields are marked *