Need help with AR 15 double firing malfunction VIDEO - Could really use some advice

[kwheezy2000]

Hello,

I posted this in the troubleshooting section but I thought I might be able to post this here as well.

I have a recurring problem with my rifle, every competition that I shoot there will be at least one instance of my rifle double, triple or more firing. I have tested my disconnecter while unloaded and I can not duplicate the hammer drop, I have tried several different disconnectors. The trigger assembly and lower parts kit are all dpms the cheapo set. The disconnector spring is installed correctly, fat side towards the trigger. I have no chattering on my bolt carrier

youtube of disconnector working as intended

http://www.youtube.com/watch?v=wtxXQgNwPxE&feature=youtu.be

Now normally if the hammer follows the bolt for a slam fire it would drop out of battery and you would have to cock it (so I'm told); my weapon is fully in battery and ready to rock even after a burst fire this is what confuses me because I have not heard this sort of problem before; I really would like to get this gun running right but I'm at a loss. I have about 6k plus rounds through it, but this gun has been doing this since I bought it in '10. This problem occurs with all different types of ammo, federal, american eagle, handloads, hornady, tula, you call it it will do it, I have tried loading hard primers and it does nothing. An estimate on the rate of occurence is about 2 or 3 times on average on 5 stages of about 28 round minimums, so maybe 150 - 200 rounds depending on how bad I am that day.

It's a bushmaster bolt & carrier, the whole upper came as a package, its the predator model; I have a bushmaster lower as well, DSA collapisble stock, with whatever buffer tube they come with; I would like to get into some regional shoots, and I highly doubt they will be as understanding as the local club shoots that I currently do. Now I don't really need a lecture on gun laws, the gun is malfunctioning, I know it's a problem but I have not been able to fix it and neither have the gun shops in my area.

Any help is appreciated, I tried to take pictures of my lower but my phone just doesn't cut it.

If there are any other videos that would help tell me and I will make them

 

[briansmithwins]

Try shooting it and maintaining control of the trigger by holding it back and letting go until you feel it reset.

I suspect you're bump firing the rifle w/o intending to.

If someone else shoots your rifle what happens?

BSW

 

[kwheezy2000]

Like I said I can't replicate the malfunction while dry firing, the disconnector works great, a distinct clunk when the disconnecter catches with about 3/4" reset after letting off.

I hold the rifle pretty hard, I have a 20" upper with rifle system, I hold right next to the FSB, with the stock collapsed almost all the way.

I have never tried to bump fire, is my stance condusive to it happening?

It doesn't happen all the time, most of the time (95%) it works perfectly fine, in fact its very accurate and I love to shoot it; people that have shot the rifle have not experienced it but then again it's not like they use it over the course of a match usually just a few shots.

 

[mshootnit]

you need try a complete trigger unit. I would try a Geissele or Wilson TTU. Reason I say this is because the Geisselle has a secondary sear and the Wilson is completely self contained so that as long as the pins fit through the unit and into the receiver on both sides you are good to go.

 

[kwheezy2000]

I guess I just have a hard time understanding why a new trigger group would fix this problem, I have put 2 DPMS LPK in this gun, the last time was by a reputable gunsmith, this trigger has even more slack and the reset is around 3/4" I just don't see how the trigger will help this, I have a 6 lb pull which I assume would make it harder to bump fire. My hammer and disconnector have no chips and very minimal wear on the bearing surfaces. I'm not trying to be difficult I just want to understand why.

 

[Rmiller31]

could be a gas issue. carrier comes back and strips of the next round but you don't have enough to reset the hammer so the hammer goes bang again.

Does this ever happen on the last round in the magazine and cause the bolt to not lock back?

I would try cleaning out your gas tube and checking for possible leaks. I'm betting somewhere you have a leak.

 

[tarosean]

I cannot tell from the video, but are you sure your trigger or hammer pins are not moving "walking"?

 

[Robert]

Please don't post the same thread in more than one sub forum.