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Subsonic .223 Loads

Blackfork talks about working up subsonic .223 loads for his suppressed AR.  Bullets moving at supersonic speeds will create a small sonic boom that can still create a noise problem.

8 Responses to “Subsonic .223 Loads”

  1. OrangeNeckInNY says:

    Question is: will it create enough pressure to cycle properly?

  2. Chuck B. says:

    I once saw this website that had subsonic .223 ammunition for sale, but that was over a year ago. I don’t know anything more about this ammunition, although I wish I did.

  3. Sebastian says:

    No… it won’t cycle the action on an AR.

  4. Wolfwood says:

    Am I missing something, or would you just need a lighter spring to allow cycling?

  5. Sebastian says:

    Wolfwood:

    Probably not. In order to cycle the action on an AR, you have to send a pressure wave down the gas tube and to the bolt carrier. The pressure wave will unlock the breech, and eject the previous cartridge, and the spring will push the bolt carrier back, strip a round out of the magazine, push it into the chamber and lock the breech. It has to do this before pressure in the barrel and gas system drops because of the bullet exiting the barrel. With a lighter spring, you could probably get lighter loads to extract better, but you could have issues with the breech not locking, or with rounds not being stripped off if the spring is weak enough.

  6. Wolfwood says:

    How would you solve the problem, then? Manual cycling on an AR is kind of a hassle (and is relatively loud). Here’s what comes to mind for me:

    1. Modify the upper receiver and bolt so it can take an AK-style extension on the bolt for manual cycling. I don’t like this solution at all.

    2. Special gas tube that takes in more gas; this is also probably a hassle.

    3. Specially-rigged piston upper. This would be expensive initially but probably cheap to modify.

    4. What about a special barrel and silencer that uses normal .223 rounds but is ported (and the ports suppressed) so as to bleed off speed between the gas tube and the muzzle?

    Just spitballing here. I’d love to get an effective suppressor for my AR and this is a great topic.

  7. Billll says:

    Change the upper to one chambered in .22 LR, which can be purchased in subsonic flavor.

    Maybe it’s just me, but it seems like making an AR into a subsonic weapon is sort of counter productive. I get visions of someone loading .50 BMG with little enough powder to accomplish the same thing, so his shooting neighbors at the range won’t be blown away my the noise and muzzle brake blast. A laudable intention, but now you have a .50 BMG with a maximum effective range of 120 yards.

    I have heard of some hard-core .22 shooters who swap the bullets in their .22 LRs to 55gr fmj in an attempt to improve their accuracy.

    The English put suppressors on .223 and larger varmint rifles, and sing the praises of such an arrangement. Yes, you still need ear protection, but apparently, not as much of it.

  8. Mad Saint Jack says:

    I remember reading (probably in a gun rag) that someone working on a subsonic .223 load decided that a .22LR could do the same job, and thus the Aguila 60g SSS round was created.

    http://www.cabelas.com/prod-1/0024232215204a.shtml

    I’ve shot them in my 22/45 and 10/22 (not suppressed) and both cycled fine.

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