AR-15 won't fire more than one round.

[Miroku]

I have a Bushmaster M4-style AR. Just to make it easier for you to get an idea of what's going on, internally it is stock except for the bolt carrier group (BCM), buffer (H3, BCM), Wilson Combat tactical trigger unit (single-stage; replaced after problem started). I got through 20-40 rounds with no issues. Then, after the case ejected, I squeezed the trigger again and heard a "click." Pulling back the charging handle, a live round ejected and I get off another shot from the next round, then another "click." Same thing, for another sixty or so rounds. From the unfired rounds, shallow indentations where the firing pin hit. Assuming that the BCG wasn't riding rearward fully and the trigger wasn't resetting completely. I cleaned the rifle, very liberally applied oil until the BCM and charging handle moved (very) smoothly, and returned to the range. I got through a few (less than 20) rounds before this started happening again. I tried pulling the BCM back halfway to reset the trigger. That worked, but it defeats the purpose of having a semi-auto rifle, doesn't it? Don't ask me what caused me to do this, but I engaged the safety and then disengaged and squeezed the trigger. BANG. Round ejected, fresh round in, click. Safety on, safety off, BANG. Safety on, safety off, BANG. You get the picture. I remember hearing a separate click aside from the safety a split second after engaging. I think it's the trigger resetting, but I'm not sure.

Would anybody be familiar enough with this type of issue to help troubleshoot it? Many thanks in advance.

[Retaks]

It sounds to me like you have too heavy of a buffer and its not letting the bcg come all the way back. Try an H or H2 buffer and see if it fixes it. Im no expert on AR but thats how it sounds to me. Im sure someone with more knowledge will chime in soon enough.

[J Krammes]

I am willing to bet you have the trigger group installed incorrectly. Something is binding on the hammer. Also, the H3 is a bit heavy for a 16" gun.

Jk

[Iraqgunz]

What ammo are you shooting? I would switch to an H buffer and standard spring and re-fire. Make sure that you have the FCG installed correctly.



I have a Bushmaster M4-style AR. Just to make it easier for you to get an idea of what's going on, internally it is stock except for the bolt carrier group (BCM), buffer (H3, BCM), Wilson Combat tactical trigger unit (single-stage; replaced after problem started). I got through 20-40 rounds with no issues. Then, after the case ejected, I squeezed the trigger again and heard a "click." Pulling back the charging handle, a live round ejected and I get off another shot from the next round, then another "click." Same thing, for another sixty or so rounds. From the unfired rounds, shallow indentations where the firing pin hit. Assuming that the BCG wasn't riding rearward fully and the trigger wasn't resetting completely. I cleaned the rifle, very liberally applied oil until the BCM and charging handle moved (very) smoothly, and returned to the range. I got through a few (less than 20) rounds before this started happening again. I tried pulling the BCM back halfway to reset the trigger. That worked, but it defeats the purpose of having a semi-auto rifle, doesn't it? Don't ask me what caused me to do this, but I engaged the safety and then disengaged and squeezed the trigger. BANG. Round ejected, fresh round in, click. Safety on, safety off, BANG. Safety on, safety off, BANG. You get the picture. I remember hearing a separate click aside from the safety a split second after engaging. I think it's the trigger resetting, but I'm not sure.

Would anybody be familiar enough with this type of issue to help troubleshoot it? Many thanks in advance.

[NoveskeFan]

As others have said, make sure the hammer spring is on top of the trigger pin. Why are you running a H3?

[MistWolf]

It definitely sounds like an FCG problem. My guess the trigger is not returning on release. As long as the trigger is held to the rear, the semi-auto sear (1) engages the hammer (2) when it's cocked to keep it from following the BCG when it returns to battery. This sear will not disengage until the trigger moves forward to it's reset position.

If the trigger is to the rear and the hammer cocked, engaging the safety will push the trigger forward and the semi-auto sear will release the hammer to be engaged by the trigger sear (4) which will release the hammer to fire the weapon when the trigger is depressed. You can test this by seperating the upper from the lower with the hammer in the released position, depress the trigger and hold it while cocking the hammer. Keep the trigger depressed and engage the safety. You will feel the trigger being pressed forward to it's reset as the safety pivots into position. In normal operation, spring pressure will press the trigger forward to it's reset. If the springs are not correctly installed (4&5), or of they are broken or worn, the trigger may not return
http://i115.photobucket.com/albums/n289/SgtSongDog/Research/Trigger.jpg

[Tweak]

sounds like the middle hammer hook is binding on the hook of the disconnector.

http://i13.photobucket.com/albums/a264/artweaker/Troubleshooting/WilsonTR-TUU-2.jpg

[PalmettoPrecision]

It sounds to me like you have too heavy of a buffer and its not letting the bcg come all the way back. Try an H or H2 buffer and see if it fixes it. Im no expert on AR but thats how it sounds to me. Im sure someone with more knowledge will chime in soon enough.

?? He clearly stated that a live round was ejected when the weapon was charged after every failure. Buffer doesn't seem to even be remotely an issue, am I wrong?


Edit: Seemed kindave harsh.

[polymorpheous]

Get rid of the Wilson trigger pack.
I think your problem will be solved.

[Miroku]

I think the error is on me. I am very new to the AR platform and am learning as I go. To answer some of your questions/concerns:

I did at one point put the original buffer back in the rifle (to try and pinpoint the problem) with no change. The buffer spring has always been stock.

I have used (for the most part) Remington white box 55 grain, Hornady TAP FPD 62 grain, and milsurp XM855. I never had a problem with the milsurp.


I have taken a look at the trigger group (several times) and everything seems to be installed correctly.

I will recheck everything and get back to you guys. Thank you all for the input.

UPDATE: After checking all of the internal parts again, I noticed the hammer spring on the right side of the weapon slipped off of the trigger pin. I swear I checked that a dozen times and never noticed it before. Thank you all for your input. Goes to show I've got a lot to learn about this system.

[Eric]

Contact Wilson Combat. (http://wilsoncombat.com/new/contact-us.asp) Your $280 trigger pack should work.