Page 3 of 4 FirstFirst 1234 LastLast
Results 21 to 30 of 32

Thread: Help me troubleshoot my SBR! (PICS ADDED)

  1. #21
    Join Date
    Dec 2008
    Location
    Hill A.F.B., Utah
    Posts
    97
    Feedback Score
    0
    This is what I did to troubleshoot my 7.5" SBR malfunctions.

    - Bought a new Gas Key & re-staked it properly.
    - Bought a heavier buffer (H2).

    As for now, it runs like a champ. I've done around 500 round without no malfunctions.

    I hope this helps.
    - Eric

  2. #22
    Join Date
    Jan 2008
    Location
    AZ-Waging jihad against crappy AR's.
    Posts
    24,902
    Feedback Score
    104 (100%)
    Are you sure that both of the "fixes" were actually needed? What led you to believe that the gas key was the culprit and not simply a changing of buffers?

    Quote Originally Posted by ginarik View Post
    This is what I did to troubleshoot my 7.5" SBR malfunctions.

    - Bought a new Gas Key & re-staked it properly.
    - Bought a heavier buffer (H2).

    As for now, it runs like a champ. I've done around 500 round without no malfunctions.

    I hope this helps.



    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. #23
    Join Date
    Sep 2010
    Location
    Co
    Posts
    171
    Feedback Score
    0
    Since no one has mentioned this. Have you tried different magazines encase you are having a magazine feed issue.
    "You done good. Remember the rules of home gun smithing: Measure it with a micrometer, mark it with chalk, cut it with a torch/dremel, grind it to fit, paint it to match with a sharpie!"

  4. #24
    Join Date
    Jun 2007
    Posts
    1,234
    Feedback Score
    0
    Yes, I used several different pmags and a USGI aluminum mag.

    I tested it again yesterday with .223, and it malfunctioned the same as before. It passed the short stroke test as well...when it functioned properly.

    Oh well. Maybe I can turn it into a blowgun or something.

  5. #25
    Join Date
    Jan 2008
    Location
    AZ-Waging jihad against crappy AR's.
    Posts
    24,902
    Feedback Score
    104 (100%)
    OK. A little recap. As I understand it, your SBR works with .223 and some 5.56?

    Odd. In any case something has occurred to me. Contact M&A and ask them what size their gas port is. Also, I think I would remove the rail and check the gas block. I have no idea if it's pinned or screwed, but still check it. I would also try and see about replacing the gas tube.

    You may also want to put it back into it's original configuration. I personally think that a 7.5" is a waste of money so I wouldn't want to sink alot into it.

    Quote Originally Posted by 1911-A1 View Post
    Yes, I used several different pmags and a USGI aluminum mag.

    I tested it again yesterday with .223, and it malfunctioned the same as before. It passed the short stroke test as well...when it functioned properly.

    Oh well. Maybe I can turn it into a blowgun or something.



    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

  6. #26
    Join Date
    Jun 2007
    Posts
    1,234
    Feedback Score
    0
    Quote Originally Posted by Iraqgunz View Post
    OK. A little recap. As I understand it, your SBR works with .223 and some 5.56?

    Odd. In any case something has occurred to me. Contact M&A and ask them what size their gas port is. Also, I think I would remove the rail and check the gas block. I have no idea if it's pinned or screwed, but still check it. I would also try and see about replacing the gas tube.

    You may also want to put it back into it's original configuration. I personally think that a 7.5" is a waste of money so I wouldn't want to sink alot into it.
    I'll be sure and do that. Since I found that .223 malfs as well as 5.56mm now, I'm leaning back toward the A5 being the culprit.

    I'll try it again with the standard Milspec RE and carbine and H2 buffs installed for one last try before I sell it off. I'm definitely not going to pour any more cash into this thing. I'm just trying to make what I have work. I bought it before I knew better, sadly.

    Fortunately, my AR knowledge has increased a great deal in the last few years. I'm currently waiting on my first KAC upper. I have an IWS lower now, and it's incredible. I suppose in a way, experiences like this with lower grade components make me appreciate the BCM/DD/Colt/KAC guns more.

    Thanks for the help!

  7. #27
    Join Date
    Apr 2009
    Posts
    79
    Feedback Score
    0
    Have you tried upgrading the extractor spring?
    www.Renegade-Armament.com
    01 FFL/03 SOT
    NRA Pistol Instructor

  8. #28
    Join Date
    Jan 2008
    Location
    AZ-Waging jihad against crappy AR's.
    Posts
    24,902
    Feedback Score
    104 (100%)
    Something I should have asked before. Do you by chance have an O-ring on your extractor spring assembly? If so, remove it.



    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

  9. #29
    Join Date
    Aug 2011
    Location
    E. Tennessee
    Posts
    2,124
    Feedback Score
    6 (100%)
    I am no expert, but it looks like the "cuts on the barrel" are the M4 feed ramps rather than a standard barrel.....if I am wrong, someone please explain/show me the difference (on an installed barrel, hard to tell when installed...IMO).
    Last edited by hotrodder636; 08-12-11 at 18:42.

  10. #30
    Join Date
    Jul 2011
    Posts
    8
    Feedback Score
    0
    Problems started after the install of a VLTOR Emod A5 combo kit?
    Standard A5 buffer is 5.3oz.
    I built a very picky AR 7.5" pistol w/stainless heavy contour barrel that did the same thing yours seems to be doing.
    I changed the buffer to an H2 w/same carbine action spring and I opened gas port up to .076 from .061 to start cycling properly.
    After that I dropped an adjustable gas block on it to adjust to ammo changes, found the sweet spot and left it there.
    I'm not saying you will need to do all that but start at the buffer weight.
    First change to lighter buffer and see if that will get your timing back. H or H2.
    Good luck.

Page 3 of 4 FirstFirst 1234 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
  •