I've been having ejection problems with my AR and have been pursuing cause and cure. I've read the FAQ's and done the requisite searches. In doing so, I found that dirt (oddly enough) can cause FTF, FTE, etc problems. My AR pulls the empty from the chamber, flips it backwards and jams the next round underneath it.

So I finally got ballsey enough to mess with the bolt. When I took the extractor off I discovered a ton of crud under it. Could that cause the ejection problem?

Extractor and ejector springs seem very strong so I haven't replaced them. Extractor doesn't seem worn, etc. I haven't gotten back to the range to see if the cleaning worked...

Okay, as of 0042zulu 13 people have read this and not one reply...

I need some experienced help here!

ok, I'll give it a shot.

It's not clear from your discription but you seem to be saying the extracted case ends up in the reciever but turned end for end.  It then interferes with feeding the next round.

I would say enough crud could cause problems but can't quantify how much or where it needs to be.  I do know that crud or brass shavings can get down around the ejector and cause problems.  I actually had a bolt lock open on the last round with the empty still stuck on the end of the bolt.

Many people, including me, recomend a heavy duty extractor spring.  Some have used a small rubber o-ring around the outside of the extractor spring.  This would be an inexpensive thing to try.

Does the bolt reliably lock open on the last round every time?

Quoted: So I finally got ballsey enough to mess with the bolt.

No, the problem is that the rifle came with a manual on how to clean and maintain it from the start.  Either you have used the manual to wipe your ass and flushed it down the toilet, or you need the original first edition military comic book style manual (with the big pictures) since surly you are retarded.

Now that I have your attention, read this,
http://www.ar15.com/content/guides/maintenance/

When the site refers to lube, it is CLP that you should be using to clean and lube the rifle.  The cheapest form of CLP currently is BreakfreeCLP.  Copper bore solvent should be used to clean the copper fouling from the bore, but the rest of the rifle should be cleaned and lubed with CLP.

P.S. If you think I have been tough on you, this is nothing. Had you turned the rifle back into the company armor in such a condition, you would be running laps up the nearest mountain for days.
We may just have to recruit your wife to inspect the weapon before you are allowed to safe it.  Really helps if she has upper body strength so she can whip it back at you dead in the chest a couple of times as she rejects each previous effort you have made to clean the rifle.

Welcome to tough love,
Dano

Ah, feel the love

Indeed I already use CLP and scrub the snot out of everything after every use. I'm sure you're right though - I bet the armorer would heave my ass out the window - thats what they did to us at the academy...

So, what I can decipher between taunts is that grundge in general can cause problems (which I knew) but that nobody can tell me whether grundge under the extractor can cause this specific problem. Hmmm...

The only fouling that is normal is a dark carbon build up.  If you keep the upper slightly lubed with CLP, then it will break down the fouling and allow the working gas pressure to blow the crap out of the rifle.

From the start, the bearing surfaces of the rifle should be lubed, then after a few hundred rounds; a few drops of CLP should be added to the carrier gas ports on a slightly cocked action.  This will allow the CLP to get back to the carrier gas chamber, and the working pressure of the cycling action will move the lube through out the rest of the action.


Now if your getting a lot of brass flakes fouling, then you will need to clean up a few areas on the rifle.

The extractor claw ends and relief channel ends for the case rim.
The feed ramps on the barrel extension (end cut burs).
The ejector opening on the bolt face.
The underside of the feed lips on the mags, and the front leading edge where the round climbs out.

Any burs on these areas will lead to the case being scraped on loading or recharging, and these flakes will find there way back into both the bolt and the action, which a fresh coat of CLP will not resolve.

YES, anything under the extractor will cause ejection problems!  Clean it up, and you may use copper cleaner and a brush on the bolt to get copper off of the face or anywhere else you might have yellow or red marks.  It is common to use a red or black extractor spring on carbines for reliable extraction, or the D-fender, or a simple small o-ring as stated in a previous post.  Most often when I come across this problem, it is the extractor spring worn, or the rubber (blue) buffer inside chewed up, or a VERY dirty chamber.

Nope. 16" barrel. DPMS lower, J&T upper.

I'm going to try getting to the range this afternoon before work to see if I have improved performance.

Also, I haven't noticed any brass fouling and it locks open on last round every time.

BTW, I do appreciate the advice...

(Edited to add brass, lock open comments)