AR-15 broke at the range...

[1stIDvet]

I was shooting my M1A and AR at the range today. Everything was great until I had a FTE, turned out to be more than just a FTE. The bolt was stuck open a 1/4 of the way and the round that was fired was still in the chamber. I eventually forced the bolt closed and separated the upper from the lower and found this...

With further inspection this was found...
(notice the perfect circle where the indexing nipple should be held in)

Has anyone had this problem or have heard of it. Im pretty pissed off and had my doubts about DPMS before. I hope a DPMS rep is on this forum to see the garbage there putting out. I had thoughts of getting a SCAR, this just might have sealed the deal. Thanks for any input...

 

[sobrbiker883]

Re: AR-15 broke at the range...

Looks like the detent was barely retained.
POF makes a milspec buffer tube that will never suffer that problem.
http://www.pof-usa.com/parts/arparts.htm

 

[1stIDvet]

Re: AR-15 broke at the range...

It was retained perfect before the day, there is broke pieces of metal down by the trigger after the buffer tube broke..

Thanks for the link. will order from there.

 

[AK10mm]

Re: AR-15 broke at the range...

Was this a Factory Rifle and did you buy it new?From you photo the tube does not look contoured to the receiver at the front,just a flat cut on the end,as FUBAR'D as it is,I can't tell if it even had a slot for the detent pin.I may even order one or two of the POF Tubes that sobrbiker 883 posted.For $40 each,it's cheap insurance.From the SN it looks like a factory rifle.I think the stripped receivers have a "K" in the SN.

 

[LoneWolfUSMC]

Re: AR-15 broke at the range...

It definitely looks like the receiver extension was not properly installed. It does not appear to be screwed in far enough. Replace it with the correct extension (contoured) and drive on.

Make sure the castle nut it properly staked and you will not have another problem with it.

 

[bohem]

Re: AR-15 broke at the range...

USMCj hit the nail on the head, something isn't installed properly. The 1 time that I've seen this happen before was a RRA lower that was assembled by a person who didn't know what they were doing. Upon proper assembly, there hasn't been a problem for almost 2000 rounds, last I asked.

My DPMS lower has close to 5k through it and nary a hitch.

 

[Bronco]

Re: AR-15 broke at the range...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: LoneWolfUSMC</div><div class="ubbcode-body">It definitely looks like the receiver extension was not properly installed. It does not appear to be screwed in far enough. Replace it with the correct extension (contoured) and drive on.

Make sure the castle nut it properly staked and you will not have another problem with it. </div></div>

Have to agree. I've seen a couple of the buffer retaining pins break, and know some guys that don't run them because of this. Something I check while cleaning, but never replaced one even with over 20 K rounds on it.

 

[Sterling Shooter]

Re: AR-15 broke at the range...

Looks like someone modified the receiver extension to get the detent in "after" the extension was installled.

I've sold a gazallion DPMS rifles at the store where I work part-time in Louisville. In the last 6 or 67 years I can only recall a handful of DPMS products in need of service or repair due to manufacuring, or material defect.

 

[1stIDvet]

Re: AR-15 broke at the range...

the rifle is factory, they only thing I have installed was the KAC rails and an ACOG.

-Also the buffer tube is as far as it can go forward, the picture up top doesn't really show it good enough. If the buffer tube were to be screwed one more full rotation the rear of the bolt would hit it when you closed the upper to the lower.

 

[hopps]

Re: AR-15 broke at the range...

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> Have to agree. I've seen a couple of the buffer retaining pins break, and know some guys that don't run them because of this. Something I check while cleaning, but never replaced one even with over 20 K rounds on it.
</div></div>

What do they run instead?

I have seen detents fail but most of the time when I see this happen it is because someone didn't install the tube correctly and or didn't tighten the nut tight enough / stake it and it backed off allowing the buffer tube to back off as well.

A buffer tube "breaking" has to be the more rare way for this to happen.

 

[bowslngr]

Re: AR-15 broke at the range...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 1stIDvet</div><div class="ubbcode-body">the rifle is factory, they only thing I have installed was the KAC rails and an ACOG.

-Also the buffer tube is as far as it can go forward, the picture up top doesn't really show it good enough. If the buffer tube were to be screwed one more full rotation the rear of the bolt would hit it when you closed the upper to the lower. </div></div>

Then screw it in another half of a full rotation. Just sayin'

 

[AK10mm]

Re: AR-15 broke at the range...

bowslngr, Half of a full rotation would put his stock upside down!!!

 

[Rovieairto]

Re: AR-15 broke at the range...

If a competent armorer built this rifle, they should have caught this.
DPMS should send you a new buffer tube (Try and get a free spanner tool as well).
If they don't/won't you should let us know.

You can fix it by filing/dremeling off the excess material that interferes with closing when the buffer tube is screwed in one more full rotation.

You can buy a new buffer tube (they are cheap).

When properly built and fed, the AR is an increadably reliable rifle.
Don't give up just yet, There are a lot of details that need to be just right when building any rifle.

 

[Bronco]

Re: AR-15 broke at the range...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: hopps</div><div class="ubbcode-body"> <div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> Have to agree. I've seen a couple of the buffer retaining pins break, and know some guys that don't run them because of this. Something I check while cleaning, but never replaced one even with over 20 K rounds on it.
</div></div>

What do they run instead?

I have seen detents fail but most of the time when I see this happen it is because someone didn't install the tube correctly and or didn't tighten the nut tight enough / stake it and it backed off allowing the buffer tube to back off as well.

A buffer tube "breaking" has to be the more rare way for this to happen. </div></div>

They don't run anything, buffer rests against the carrier. Bit harder to pop the top, but takes one failure option off the table. I'm not advocating this, just that it is done.

 

[dustinlotz]

Re: AR-15 broke at the range...

+1

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: LoneWolfUSMC</div><div class="ubbcode-body">It definitely looks like the receiver extension was not properly installed. It does not appear to be screwed in far enough. Replace it with the correct extension (contoured) and drive on.

Make sure the castle nut it properly staked and you will not have another problem with it.</div></div>

 

[1stIDvet]

Re: AR-15 broke at the range...

The buffer tube was installed all the way forward, in the picture it doesn't look it but like i had said, if you were to screw it one full rotation it would be too far forward.

 

[1stIDvet]

Re: AR-15 broke at the range...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bowslngr</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 1stIDvet</div><div class="ubbcode-body">the rifle is factory, they only thing I have installed was the KAC rails and an ACOG.

-Also the buffer tube is as far as it can go forward, the picture up top doesn't really show it good enough. If the buffer tube were to be screwed one more full rotation the rear of the bolt would hit it when you closed the upper to the lower. </div></div>

Then screw it in another half of a full rotation. Just sayin' </div></div>

Ya ill try that.... thanks.........

 

[sobrbiker883]

Re: AR-15 broke at the range...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bowslngr</div><div class="ubbcode-body">
Then screw it in another half of a full rotation. Just sayin' </div></div>

As said above, then your buttstock will be upside down

 

[Rovieairto]

Re: AR-15 broke at the range...

Just shoot it Bren style then.

 

[telcolineman]

Re: AR-15 broke at the range...

Buffer tube was not screwed in far enough, I had this happen on my first build. Screw it in until it just clears the nipple on the detent, None of my buffer tubes have a slot cut for the detent and I run RRA Bushy and Armailte tubes. From the pic it looks like it can be screwed in farther which will prevent this from happening again, I personally would not reuse that buffer tube again because of the metal missing and possable fatigue

 

[1stIDvet]

Re: AR-15 broke at the range...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: telcolineman</div><div class="ubbcode-body">Buffer tube was not screwed in far enough, I had this happen on my first build. Screw it in until it just clears the nipple on the detent, None of my buffer tubes have a slot cut for the detent and I run RRA Bushy and Armailte tubes. From the pic it looks like it can be screwed in farther which will prevent this from happening again, I personally would not reuse that buffer tube again because of the metal missing and possable fatigue </div></div>

It was screwed in all the way. the buffer tube just failed, as in it broke. New buffer tube is on the way.

 

[cz777]

Re: AR-15 broke at the range...

wow the moo ! look up PWS site for their tube with dent extension slot to cover the open threads of the lower in front of the tube opening ....

 

[Muttt]

Re: AR-15 broke at the range...

Simple fix ..... the factory should make this right. Send them the pics with your email.

Mutt

 

[1stIDvet]

Re: AR-15 broke at the range...

I called DPMS, they wanted me to send my whole lower, at my expense. I said fuck that and bought a new tube for $25. Shoots fine again.