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Author Topic: Barrel minimums for suppressors  (Read 621 times)

Jk17766

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Barrel minimums for suppressors
« on: January 22, 2021, 01:14:04 pm »
Hello,
I am curious as to why barrel minimums for suppressors exist? For instance one of my cans is rated for 10"+.
Is this due to the suppressor not being able to withstand the pressure from a smaller barrel, or is it more because the suppressor was never tested at a lower length?
I have no plan to go against their minimums, but I am just curious as to why they set them.
TIA

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    870policemag

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    Re: Barrel minimums for suppressors
    « Reply #1 on: January 22, 2021, 02:00:48 pm »
    I'm no professional but I think it has something to do with higher temps, backpressure and bullet stabilization. I bought a Surefire SB for this same reason. It has a slightly larger bore/baffle diameter to help to stabilize  bullets out of sub 9" barrels. That larger bore diameter is also supposed to help gas flow through the can and decrease gas blow back into the shooters face.

    I'm sure someone with more knowledge will chime in soon enough.
    Bullets are the only things that do their job only after they're fired.

    www.mesapawn.net

    CZ

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    Re: Barrel minimums for suppressors
    « Reply #2 on: January 22, 2021, 03:17:42 pm »
    Barrel length is a determining factor in the suppressors design.

    A shorter barrel allows more un-burned powder to be burned inside the suppressor, has more blast pressure, more flame and affects sound performance and longevity too.

    Most cans designed for a shorter barrel will be heavier and made to withstand these things.

    The sound suppression on a short barrel will normally be a lot less than what you get with a longer one too.

    AZ Husker

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    Re: Barrel minimums for suppressors
    « Reply #3 on: January 24, 2021, 04:02:18 am »
    After much research and interrogating the nice folks at the Mr Silencer shop in Mesa I chose a Rugged brand Obsidian9. You can use it either in 5" or 8" length for the amount of suppression you want. It is also very easy to disassemble and clean, unlike many others. I'll attach a link to the model on the Rugged website, but the price was much cheaper at the Mesa shop. They are truly a one-stop shop providing a kiosk for the paperwork, setting up a trust, and having lower prices. Mine took just under a year, but there is no explaining the Fed's time frame.
    https://ruggedsuppressors.com/pistol-suppressors/obsidian9/

    « Last Edit: January 24, 2021, 04:08:38 am by AZ Husker »

    CZ

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    Re: Barrel minimums for suppressors
    « Reply #4 on: January 24, 2021, 10:38:57 am »
    After much research and interrogating the nice folks at the Mr Silencer shop in Mesa I chose a Rugged brand Obsidian9. You can use it either in 5" or 8" length for the amount of suppression you want. It is also very easy to disassemble and clean, unlike many others. I'll attach a link to the model on the Rugged website, but the price was much cheaper at the Mesa shop. They are truly a one-stop shop providing a kiosk for the paperwork, setting up a trust, and having lower prices. Mine took just under a year, but there is no explaining the Fed's time frame.
    https://ruggedsuppressors.com/pistol-suppressors/obsidian9/

    It will be interesting to see what the wait times will be on form 4's  I like the Obsidian, it looks like a good can.  For me I just hate the wait so I prefer to build my own since form 1s are still only a month or so wait times...

    ynotaz

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    Re: Barrel minimums for suppressors
    « Reply #5 on: January 24, 2021, 12:33:35 pm »
    To the op, check the manufacturers specs of the can you're interested in for your answer. 

    I have a couple, for different purposes, but the only one rated for almost anything I shoot is a YHM phantom.  It's rated down to 10" and for machineguns.  It is heavy since it was built for the pressure and heat generated under those circumstances.  It has about 50K rounds through it of everything, 22lr, 5.56, .243, 300 whisper, 7.62, 7.68, and has run on 22lr sub-gun and 5.56 machinegun with no issues.

    It is a 7.62 can but because of design and volume quiets a 5.56 as well as a dedicated can.   
    Finally found my new sig:

    https://youtu.be/yuEBBwJdjhQ?t=46

    delta6

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    Re: Barrel minimums for suppressors
    « Reply #6 on: January 25, 2021, 10:42:07 am »
    Hello,
    I am curious as to why barrel minimums for suppressors exist? For instance one of my cans is rated for 10"+.
    Is this due to the suppressor not being able to withstand the pressure from a smaller barrel, or is it more because the suppressor was never tested at a lower length?
    I have no plan to go against their minimums, but I am just curious as to why they set them.
    TIA
    I sent an email to a shooting partner with the OP's question. I figured we should go to the source for an answer.

    Phil:
    Hope all is well today.
    Attached is a question popped up on a local board.

    His reply.

    The answer is both (but primarily a pressure issue) plus bullet instability due to inadequate rotational velocity. I am attaching an article I wrote showing bore pressure at uncorking vs barrel length for 5.56 (also velocity issues with barrel length). Basically, higher bore pressure at uncorking yields higher entrance chamber pressure in the can. Also, while a can may be able to withstand the pressure when cold, after 100 rounds when yield strength drops to 60% of cold, the can may rupture, swell, or stretch.

    For rotational stability (about 17K rpm for 5.56 as I recall) it is an issue of linear velocity and twist rate. Also, without at least one full rotation of the rifling, stability is an issue.
    Hope this helps.

    Phil...


    CGIS

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    Re: Barrel minimums for suppressors
    « Reply #7 on: March 21, 2021, 01:58:00 am »
    Guys do it right the first time and go OSS. No barrel restrictions with their flow through technology.

    If you’re LEO or military they offer a 30% discount or $400 off. You have to apply and submit proper current or retired credentials. It’s called the PASS Program. Well worth it.

    And also Liberty Defense sells the only recommended wrap for your OSS can. They will cost you $245+ though but they can withstand continuous heat at 2000 F and burst up to 3000 F.

    I looked at a dozen different suppressors and saw all the in house testing against OSS and none of them beat OSS, especially with SBRs/pistols. Surefire sucked big time. Couldn’t even make it to a 5th cycle without failing the US military suppressor testing. OSS got to a 12th cycle and the US military said they had seen enough.

    I went with an OSS 556 Ti Suppressor with a Liberty Defense wrap. Done and done.
    « Last Edit: March 21, 2021, 02:04:47 am by CGIS »

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