Installing factory jam nut and muzzle brake

FN Forum

Google Search
Results 1 to 10 of 10
Thanks Tree11Thanks
  • 1 Post By badz2801
  • 4 Post By FS2KSTD
  • 2 Post By FS2KSTD
  • 3 Post By FS2KSTD
  • 1 Post By HK SD9 Tactical

Thread: Installing factory jam nut and muzzle brake

  1. #1
    Junior Member
    Join Date
    Dec 2012
    Posts
    20
    Thanked
    10 times

    Installing factory jam nut and muzzle brake

    Hi

    I bet this is a rare question.

    How on earth do you get the factory brake and jam nut to index correctly?

    Mine seems to stop a 1/4 turn before being correctly indexed. I don't recall removing a shim.


  2. #2
    Junior Member
    Join Date
    Dec 2012
    Posts
    20
    Thanked
    10 times
    Figured it out.

    a. Screw on jam until it stops.

    b. blue locktite

    c. Screw on brake and rotate til desired location as close to jam nut as possible.

    d. rotate jam nut to brake.

    e. tighten jam nut and brake at same time.
    surfininsm thanked this.

  3. #3
    Senior Member FS2KSTD's Avatar
    Join Date
    Apr 2009
    Location
    Eastern WA
    Posts
    2,881
    Thanked
    1904 times
    Quote Originally Posted by badz2801 View Post
    Figured it out.

    a. Screw on jam until it stops.

    b. blue locktite

    c. Screw on brake and rotate til desired location as close to jam nut as possible.

    d. rotate jam nut to brake.

    e. tighten jam nut and brake at same time.
    The 242 will be non-existent/degraded by the end of the first full magazine... unnecessary and not applicable. The rest of your procedure description is correct. Glad you got it figured out.
    STL, Kakashi66218, LESTER and 1 others thanked this.
    Μολὼν λάβε

  4. Remove Advertisements
    FNForum.net
    Advertisements
     

  5. #4
    Junior Member
    Join Date
    Dec 2012
    Posts
    20
    Thanked
    10 times
    Pretty sure the factory torques these down past recommended levels. I've used both rocksett and blue locktite both are easy to break loose compared to factory installs. Maybe I'm just not putting enough of it after the cleaning?

  6. #5
    Senior Member FS2KSTD's Avatar
    Join Date
    Apr 2009
    Location
    Eastern WA
    Posts
    2,881
    Thanked
    1904 times
    Quote Originally Posted by badz2801 View Post
    Pretty sure the factory torques these down past recommended levels. I've used both rocksett and blue locktite both are easy to break loose compared to factory installs. Maybe I'm just not putting enough of it after the cleaning?
    A jam nut secures a muzzle device using reverse tension where a locking agent is securing with frictional(bonding) thread tension... different birds. No locking agent necessary when using a jam nut system but the proper "umph" is required.
    LESTER and akitainu thanked this.
    Μολὼν λάβε

  7. #6
    Junior Member
    Join Date
    Dec 2012
    Posts
    20
    Thanked
    10 times
    i was discussing muzzle attachments in general (outside of the scar with the jam nut)...sorry I didn't specify. Anytime ive removed a factory brake or flash hider is been a PITA especially for anything which was to be suppressed.
    Last edited by badz2801; 03-16-2017 at 11:38 PM.

  8. #7
    Senior Member FS2KSTD's Avatar
    Join Date
    Apr 2009
    Location
    Eastern WA
    Posts
    2,881
    Thanked
    1904 times
    With Rocksett, prep is the key... the thread surface has to be completely degreased prior to applying fresh Rocksett, then torque to spec. Also helps applying on a warm surface so a heat gun prior to application works well.
    LESTER, akitainu and STL thanked this.
    Μολὼν λάβε

  9. #8
    Senior Member ranger56528's Avatar
    Join Date
    Mar 2015
    Location
    West Central Mn
    Posts
    169
    Thanked
    105 times
    Quote Originally Posted by FS2KSTD View Post
    A jam nut secures a muzzle device using reverse tension where a locking agent is securing with frictional(bonding) thread tension... different birds. No locking agent necessary when using a jam nut system but the proper "umph" is required.
    + 1 and no locktite needed.

  10. #9
    Member 300blkout's Avatar
    Join Date
    Dec 2016
    Posts
    51
    Thanked
    25 times
    Quote Originally Posted by badz2801 View Post
    Pretty sure the factory torques these down past recommended levels. I've used both rocksett and blue locktite both are easy to break loose compared to factory installs. Maybe I'm just not putting enough of it after the cleaning?
    How hard is it to break rocksett free? Do I need to use a heat gun or torch?

    Sent from my SAMSUNG-SM-N920A using Tapatalk

  11. #10
    Administrator
    FN Supporter
    HK SD9 Tactical's Avatar
    Join Date
    Apr 2007
    Location
    Florida
    Posts
    9,335
    Thanked
    6319 times
    Quote Originally Posted by 300blkout View Post
    How hard is it to break rocksett free? Do I need to use a heat gun or torch?

    Sent from my SAMSUNG-SM-N920A using Tapatalk
    Soak in water for 24 hours.....
    FS2KSTD thanked this.
    "We hang the petty thieves and appoint the great ones to public office." - Aesop

Sponsored Links

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Similar Threads

  1. WTS SCAR 17 PWS Muzzle Brake & Jam Nut
    By yz454ever in forum FN Guns and FN items For Sale
    Replies: 1
    Last Post: 12-18-2015, 04:49 PM
  2. Wtb Scar 17 muzzle jam nut
    By rusty tweezers in forum Want to Buy
    Replies: 0
    Last Post: 12-15-2015, 10:31 AM
  3. Replies: 13
    Last Post: 10-24-2014, 04:22 PM
  4. Keep jam nut after replacing muzzle brake on 17?
    By sACR4466 in forum SCAR Accessories, Scopes & Mods
    Replies: 7
    Last Post: 03-10-2014, 08:52 PM
  5. Installing a muzzle brake....
    By meatwaggon in forum FN SCAR 17S
    Replies: 0
    Last Post: 03-23-2013, 08:01 PM