Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 22

Thread: What could make a semi fire a burst?

  1. #11
    Join Date
    Jul 2006
    Posts
    2,207
    Feedback Score
    7 (100%)
    The hammer spring is not in right and is not detenting the trigger pin, so the trigger pin has walked out a bit, allowing the trigger to go crooked, so it can't interact with the hammer like it's supposed to, but you didn't mention any pins sticking out. So I think more likely, the disconnector is holding the hammer just enough to let the thing work semi most of the time, but it's right on the edge, so sometimes the counter-recoil is enough to jar the hammer off the disconnector. With the strigger still pulled from the previous shot, it goes bang. My guesses...... either way it's something that needs to get fixed right away.
    Last edited by Ned Christiansen; 04-23-09 at 23:29.

  2. #12
    Join Date
    Nov 2007
    Location
    PA
    Posts
    1,174
    Feedback Score
    7 (100%)
    Quote Originally Posted by Ned Christiansen View Post
    The hammer spring is not in right and is not detenting the trigger pin, so the trigger pin has walked out a bit, allowing the trigger to go crooked, so it can't interact with the hammer like it's supposed to, but you didn't mention any pins sticking out. So I think more likely, the disconnector is holding the hammer just enough to let the thing work semi most of the time, but it's right on the edge, so sometimes the counter-recoil is enough to jar the hammer off the disconnector. With the strigger still pulled from the previous shot, it goes bang. My guesses...... either way it's something that needs to get fixed right away.
    I popped it right open as soon as it happened and took a quick look. The FCG pins were both flush.

    Disconnector still had 1/16" or better of engagement onto the hammer, and I could NOT get it to double in dozens of dry fires.

    I could maybe get a picture of the disconnector to hammer relationship, it certainly is generous.

  3. #13
    Join Date
    Nov 2007
    Location
    PA
    Posts
    1,174
    Feedback Score
    7 (100%)
    Quote Originally Posted by Iraqgunz View Post
    Make sure that you have a semi-auto selector lever and not a full-auto selector lever in the weapon. Also, check the disconnector and spring as I believe that is where your problem lies. A few things to ask yourself.

    1. Who assembled the weapon and what parts were used?

    2. How many rounds have been put through the weapon?

    Though you say you checked already and I believe you these are the only plausible reason that I can think of.
    The gun is a stock Bushy. I know the selector is semi, and the disconnector is a m16 style that had the back part milled down to sit flush with the sides of the m16 trigger I checked all of it when I ripped it open later, just to make sure no-one had swapped any parts in it. (we have drawers full of Colt m16 parts laying around, none were in this gun).

    Gun has maybe 2-3k through it.
    Last edited by Jim D; 04-24-09 at 02:29.

  4. #14
    Join Date
    Dec 2008
    Location
    Texas
    Posts
    79
    Feedback Score
    0
    Quote Originally Posted by CoolBreeze View Post
    I witnessed a semi-auto Bushmaster go 3 round burst the other day. It fired a 3 round burst on the shooter, then as they had a moment of "wtf!?" and began to remove the gun from their shoulder and set it down...it fired off another round.


    So it fired a 3 round burst, then fired another single round sans trigger manipulation after the burst?


    Was the shooter deep into sustained rapid fire? Possibility of Cook offs?


    FCG malfunction covers the possibility of a burst during normal firing, but another round firing after the cycle of operations is complete and the FCG/Bolt Carrier are static is another animal. The kinetic energy was already spent and hammers following the bolt home/slippage is unlikely.


    I'd go with replacing the FCG in any case. Cheap insurance to prevent a serious problem down the road in the hands of another shooter with less muzzle awareness.
    Last edited by Hell_Bent; 04-24-09 at 16:13.

  5. #15
    Join Date
    Nov 2007
    Location
    PA
    Posts
    1,174
    Feedback Score
    7 (100%)
    Quote Originally Posted by Hell_Bent View Post
    So it fired a 3 round burst, then fired another single round sans trigger manipulation after the burst?


    Was the shooter deep into sustained rapid fire? Possibility of Cook offs?


    FCG malfunction covers the possibility of a burst during normal firing, but another round firing after the cycle of operations is complete and the FCG/Bolt Carrier are static is another animal. The kinetic energy was already spent and hammers following the bolt home/slippage is unlikely.


    I'd go with replacing the FCG in any case. Cheap insurance to prevent a serious problem down the road in the hands of another shooter with less muzzle awareness.
    yeah, that's what both the shooter and I both witnesses. The FCG has been replaced... Just dunno what could have caused it.

  6. #16
    Join Date
    Jul 2006
    Posts
    4,922
    Feedback Score
    4 (100%)
    Quote Originally Posted by CoolBreeze View Post
    I popped it right open as soon as it happened and took a quick look. The FCG pins were both flush.

    Disconnector still had 1/16" or better of engagement onto the hammer, and I could NOT get it to double in dozens of dry fires.

    I could maybe get a picture of the disconnector to hammer relationship, it certainly is generous.
    It is more than engament trave.

    How stiff is the disconnector spring?
    My brother saw Deliverance and bought a Bow. I saw Deliverance and bought an AR-15.

  7. #17
    Join Date
    Aug 2006
    Location
    A-stan or MI or _________
    Posts
    3,652
    Feedback Score
    1 (100%)
    One time I didn't realize I put .154 trigger/hammer pins in a Colt 6920...took it to the range and had 2 round bursts. I quickly figured it out and put the gun back in the case.
    Praise be to the LORD my Rock, who trains my hands for war, my fingers for battle. Psalm 144:1

    Owner of MI-TAC, LLC .

    @MichiganTactical

  8. #18
    Join Date
    Feb 2007
    Location
    AZ
    Posts
    2,626
    Feedback Score
    0
    Quote Originally Posted by Dave L. View Post
    One time I didn't realize I put .154 trigger/hammer pins in a Colt 6920...took it to the range and had 2 round bursts. I quickly figured it out and put the gun back in the case.
    LOL thats a oh CRAP!
    Last edited by Shihan; 04-25-09 at 01:34.

  9. #19
    Join Date
    Nov 2007
    Location
    PA
    Posts
    1,174
    Feedback Score
    7 (100%)
    Quote Originally Posted by Heavy Metal View Post
    It is more than engament trave.

    How stiff is the disconnector spring?
    Someone else ripped out the guys and replaced all of the FCG parts. When I inspected it, I could not get it to "double"...he says he got it to go once when he release the trigger super slowly.

    I dunno if this could have been an un-intentional bump-fire, or the disconnecter was RIGHT at the point where it could have possibly happened.

    I was just stumped by it, as I couldn't get it to double in my hands...and this isn't the first disconnector I've seen needing to get replaced on an AR.

    I dunno, thanks for the help though, guys!

  10. #20
    Join Date
    Jul 2006
    Posts
    2,207
    Feedback Score
    7 (100%)
    "Got it to go releasing the trigger super-slowly"-- that is the disconnector letting loose of the hammer before the sear is in place to catch it.

Page 2 of 3 FirstFirst 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
  •