Boogered up my AR. [PICS]

[Cheeseybacon]

I posted this already on the TheHighRoad.org but I thought I'd post it again here as well in hopes of a quicker response...

I was blastin' away with my Bushmaster this past Friday when suddenly it stopped firing. I instantly assumed it had jammed as a result of my new magazines, but amazingly they have been doing their job flawlessly thus far. So I pulled the mag, cleared the chamber, and pulled it apart. This is what came out...





What exactly am I looking at?
Is this a common failure?
What should I order to fix it?
I've just bearly put 500 rounds through this thing, is there a better version of these parts that would be less likely to fail so soon?

Thanks Folks.

[KeithPA]

Can you put the pin back in? (right now). If so, your tube is too far back, I see you have a sling mount/spacer on it. Possibly you didn't adjust it forward enough when putting that on?

It looks like your tube is back farther than it should be and thus not keeping the pin down. The spring looks like it was stretched ,when the pin came up, by the buffer tube.

[snuffy19608]

Yeah,looks like a new spring and a little adjusting on the tube and you'll be back at it. Good luck.

[ssom003]

Not that bad...
You'll need a new buffer retainer spring...
Your receiver extension tube need to be just a llitle bit over the buffer retainer so it won't pop out again...

[Lycanthrope]

Looks like you tripped a few off without the buffer retainer being held in check by the telescoping stock. You wind the stock in just far enough to keep the buffer retainer and spring compressed.

No major boogering.


Lycansmallpartsthrope

[PA Rifleman]

Agreed...I'd look at the buffer tube depth in the lower receiver. It might need another turn. It isn't serious and very easy to fix. It should partially cover the detent pin bore enough to capture the flange, but the tip should protude high enough to arrest the buffer core.

He should replace the detente spring. Official term is buffer retainer & buffer retainer spring. Click here for exploded view of Bushmaster AR-15. I suggest using the correct spanner wrench for loosening the buffer core lock ring, as a lot of folks hold screwdrivers against the castellations and give the screwdriver a whack. Judging by the appearance of your lock ring, you've been spared this experience.




Does it look like this photo? Click on it to enlarge. Note how the buffer retaining pin is partially covered.

[fultonCoShooter]

its a easy fix and it does look like your buffer tube is out to far. I also noticed that the castle nut and receiver plate do not look like they were staked to keep the castle nut from coming loose.

[Xringshooter]

What fCS said, buffer tube definitely looks like its not in far enough to completely hold the buffer retainer. I put the tube in until it just touches the pin and then back it off so that the pin moves easily (1 or 2 thousandths). Not expensive to fix. But do remember to stake the nut and plate after you get it in the correct position.

[Cheeseybacon]

Thanks for the suggestions guys. I'll hafta start the search for a spring.
Any chance that someone here knows if there are any shops in the Franklin county area that keep this spring in stock? I'd like to avoid paying $5 to ship a $1.50 part, if it's possible.

So does anyone know why this spring would fail like it did? The rifle is completely stock, so I haven't tinkered or modified any of it (yet), nor have I disassembled any part of the lower receiver, that's why I'm confused by everyone saying that the buffer tube is too far out. Perhaps the guy that originally assembled my rifle at the factory was a little hungover from the night before?

[KeithPA]

Like I said before, can you put the pin in right now? If so it's the tube is too far back.

If you sigline is correct, call bushmaster about it. I've had to order small peices i've lost before and they didn't charge me anything to ship. It's worth at shot at least.