Questions about Silencers on an MP15-22

Discussion in 'NFA Firearms & Related Items' started by Mp15-22, Mar 21, 2010.

  1. Mp15-22

    Mp15-22 Member

    Mar 17, 2010
    I have an smith&wesson MP15-22 With no barrel thread, and i was wondering if i can atach a silencer to it i know that advanced armament co. (AAC) have some silencers for .22 lr, so, my real question is: can i atach a silencer even if the bore is not threaded, or do i have to make a thread to the bore in order to attach one, any comments will be appreciated. Thanks

    ill already find out if im allowed to have silencers were i live. So thats not an issue.
  2. old semperfi

    old semperfi Active Member

    Aug 27, 2009
    i live in southern indiana,old country boy at hear
    Re: Qiestions about Silencers on an MP15-22

    i doubt that you can find a silencer that will work anyway but screw on,so you will have to thread barrel.i also know that if you live in the united states you must have a permit.if all else is ok b-4 you thread barrel you first must find out true diameter and then see if anyone makes a silencer for it.there is one other thing,you will have to shoot sub sonic ammo for it and a silencer wears out every time you shoot it. old semperfi

  3. Bill DeShivs

    Bill DeShivs Well-Known Member

    Apr 7, 2006
    Re: Qiestions about Silencers on an MP15-22

    There are no federal permits for silencers. You pay a $200 one-time tax, fill out the paperwork, and get the silencer. Most modern silencers don't wear out, and replacement parts are available. Standard velocity and sub sonic ammunition will give the best results, but you can use high velocity ammo. It will still have the sonic crack, but the muzzle report will be substantialy reduced.
  4. Alpo

    Alpo Well-Known Member

    Feb 3, 2007
    NW Florida
    Re: Qiestions about Silencers on an MP15-22

    I've seen an attachment where you had a two-lobed thing on the end of the muzzle, and the can had a matching hole. You put the can on the barrel and turn it a quarter turn. Locked in tight.

    Attached Files:

  5. WoofersInc

    WoofersInc New Member

    Jan 30, 2010
    Unfortunately you will have to have the barrel threaded. Most 22 suppressors will use 1/2x28 threads and the barrel on the S&W can easily be threaded for this pitch.

    Also as pointed out, a good quality suppressor will NOT wear out each time you use it. The only issue for some is if the suppressor is a sealed unit, you will get lead build-up inside it. Most manufacturers offer a cleaning service in which you send in your suppressor and they usually will replace the baffle stack inside the can. It will take many thousands of rounds though before a suppressor would get to the point of needing to be sent in.

    By getting a suppressor that can be taken apart you will avoid any of this issue.
  6. xring

    xring New Member

    May 5, 2010
    Most suppressosors are not user servsable by law. They must be made in a way that the end user can't get into them. And too do so would violate Fed law.
  7. Shopnut

    Shopnut Former Guest

    Jun 13, 2010
    Pac NW
    xring, if you have a link to the law that supports the three claims you made, please post it. No need to put a damper on things by claming there are more restrictions than actually exist.

    I am making my own 22 caliber silencer for my P-22 and 10/22 rifle. There are no federal laws prohibiting servicing of a silencer. According to the ATF's FAQ a form 1 builder can not replace parts or make repairs that change the bore or lengthen the tube. There are no laws that prohibit opening up the silencer for cleaning or repairing parts. If I need to replace parts in the future, I have to either submit another form 1 (and another $200), obtain a license and class 2 SOT or send it to an SOT class 2 for repair.

    Here are a few links; These links are no substitute for actually reading the law, but they are helpful.

    You might want to check out . You need an email address other than a Gmail or Yahoo to register, but lurking there like I do can be very educational. I am sort of copying some of what I see there as some posters are kind enough to post drawings or photos of the baffles they use.

    Edited to add; Subsonic ammo is not required when using a silencer. Subsonic bullets make less noise due to no sonic boom and can be much less noisy when less powder is used. Even subsonic bullets can make a humming sound when flying through the air, and they can be loud when impacting the target. I was rather impressed the first time I heard a suppressed ar-15 at the rifle range. It was not quiet like a suppressed 22 rim fire rifle, but the harsh noise was dampened very much.
    Last edited: Jul 2, 2010
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