Page 1 of 4 123 ... LastLast
Results 1 to 10 of 34

Thread: Getting FSB pins in

  1. #1
    Join Date
    Feb 2008
    Posts
    728
    Feedback Score
    3 (100%)

    Getting FSB pins in

    I was doing an upper build with my son today. I removed the FSB from a new barrel for rail installation. Because it was a new barrel (DD), the FSB pins were loose on arrival. When I replaced the FSB and set to putting the FSB pins in, the tapered pins would not fully seat in the FSB. As of now, one pin protrudes by about 0.07", the other by 0.09". The recesses in the pin holes (the left side) are just about the same, so the pins are the correct size.

    When pounding on the pins, I started with a 'smith hammer and brass punch, then aluminum, then steel, going to a heavier (carpenter) hammer along the way. I gave it more than a few good blows (not like a removal, but pretty good). The FSB was well supported and solidly backed.

    While I have had less than perfect FSB installations before, I have never had pins protrude this much. They seem solidly in, but I have begun to mushroom the heads. Should I start over, get new pins and start over, not worry about it? Advice?
    Last edited by Amicus; 12-04-11 at 22:16.
    'That whole effort was held together by sweat, shame, and a tiny bit of pride.' -- Son of Commander Paisley

  2. #2
    Join Date
    Jan 2008
    Location
    AZ-Waging jihad against crappy AR's.
    Posts
    24,902
    Feedback Score
    104 (100%)
    Did you put the pins in the same holes? The whole FSB removal and installation process can be very tricky and they don't always like to go back together.



    Owner/Instructor at Semper Paratus Arms

    Facebook: https://www.facebook.com/SemperParatusArms/

    Semper Paratus Arms AR15 Armorer Course http://www.semperparatusarms.com/cou...-registration/

    M4C Misc. Training and Course Announcements- http://www.m4carbine.net/forumdisplay.php?f=141

    Master Armorer/R&D at SIONICS Weapon Systems- http://sionicsweaponsystems.com

  3. #3
    Join Date
    Feb 2008
    Posts
    728
    Feedback Score
    3 (100%)
    Quote Originally Posted by Iraqgunz View Post
    Did you put the pins in the same holes? The whole FSB removal and installation process can be very tricky and they don't always like to go back together.
    Can't say. They were mixed up on extraction. I would have preferred putting them back in the same holes, but ...

    I was not sure if it mattered because, to my knowledge, the pins had not been fully installed (new barrel and the pins were not fully seated).

    Should I pull the pins and swap?
    'That whole effort was held together by sweat, shame, and a tiny bit of pride.' -- Son of Commander Paisley

  4. #4
    Join Date
    Dec 2011
    Posts
    25
    Feedback Score
    0
    As long as they're tight, and they protrude through both sides, at least a little, I wouldn't worry about it. A press is really the best way to put them in, but a 3 lb mini sledge will do the trick in a pinch.

  5. #5
    Join Date
    Mar 2010
    Posts
    43
    Feedback Score
    10 (100%)
    This post was timely for me as I am about to venture by shaving down my first FSB and I was looking for issues to keep an eye on

  6. #6
    Join Date
    Dec 2008
    Posts
    848
    Feedback Score
    0
    I've got a DD custom URG with FSB and the small end of the pins do not protrude out from the other side of the FSB. They aslo aren't coming out unless I REALLY want them out. It also has somewhere around 750 rounds through it with no trouble, and almost no windage adjustment necessary on the rear sight.

    Don't worry about it, your barrel/FSB are fine.

  7. #7
    Join Date
    Jun 2009
    Location
    SW Florida
    Posts
    37
    Feedback Score
    38 (100%)
    Look at Colt FSB pins. they don't seat flush either. Finish the build, shoot a few hundred rounds than check the pins. If they are still tight than your good. If after shooting you decide you need to replace them than your no worse off than now.

  8. #8
    Join Date
    Sep 2007
    Location
    AZ
    Posts
    27,217
    Feedback Score
    14 (100%)
    Quote Originally Posted by Outlaw621 View Post
    Look at Colt FSB pins. they don't seat flush either.
    Yeah... They stick out a little on both sides.
    "You people have too much time on your hands." - scottryan

  9. #9
    Join Date
    Mar 2010
    Posts
    43
    Feedback Score
    10 (100%)
    Is there a certain punch that would make the job easier? I believe I read somewhere that a concave tip is the way to go...

  10. #10
    Join Date
    Sep 2007
    Location
    AZ
    Posts
    27,217
    Feedback Score
    14 (100%)
    Quote Originally Posted by backfist View Post
    Is there a certain punch that would make the job easier? I believe I read somewhere that a concave tip is the way to go...
    The hardware store has a fat nail set punch that's perfect. I foret which size or number it was.... but the tip is perfect for drifting taper pins.
    "You people have too much time on your hands." - scottryan

Page 1 of 4 123 ... LastLast

Bookmarks

Posting Permissions

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