UPDATE:
Ok I got the little guy to work again.  I think.  I only put 30rds (xm193) through it but so far so good.  I replaced the ejector spring.  The old one was very dirty.  It has some waxy skin hanging off it (CLP residue?).  I also replaced the extractor spring with a Wolf x-power unit.  The Wolf one was a little harder to put in because it was a little longer and much stronger.  I think the real problem is was with the ejector spring as it was just really messy looking.  With the few rounds I shot I noticed the brass was defiantly hitting the brass defector, because the brass was going about 45 degrees forward and to the right, 6ft from the gun when standing.  I also bought a Wolf x-power spring because I thought the bolt might have a little too much rearward velocity but I have not put it in yet.  I look forward to putting a case of wolf through this little AR again.  Thanks for the help all.


Hey.  I am stumped here guys and don’t really know what to do.  I have posted this problem a few times but have gotten nowhere.  So here it is again.  I have a Bushmaster 16” lightweight upper on a Cav arms lower.  I had put maybe 1200rds through it without a hitch.  Now all the sudden the thing is really messed up.  I don’t get it, I have changed nothing but yet the rifle has changed on me.  First off the A2 sights are now mysteriously off at 100yds by over 6”.  I have I have checked all the knobs and adjustments multiple times but they are the same as they were whey I first sighted the gun in over a year ago.  I have re sighted it in but I am clueless why this happened.  Second the gun now jams frequently, on the order of 1 or 2 times per 20rds.  All jams have been failures to eject.  This I also don’t understand this because all parts function as they should as describe in the trouble shooting guide.  The ejector spring is as strong as my other ARs if not stronger as is the extractor spring.  I initially thought it might be short stroking but that can’t be the case because the gun locks back on an empty mag every time.  Also this rifle has loads of recoil; I can feel the buffer slamming the end the receiver extension every time it fires.  What the heck is wrong with this thing?  It shot like a dream for the last year and now it is a peace of crap.      


Here are what the jams look like

Bullet in chamber, brass caught by bolt



Ditto but fliped around brass.


Last shot on an empty mag, bolt locked back and brass just did not fly out.  

chamber fouling causing stuck cases or increased chamber pressures?


gas port erosion causing too much gas to be bled off?


what do the cases look like after being fired?

Just cleaned the whole thing yesterday.  Still messed up.  The brass are nice and clean (XM193).

Check your extractor... Look for chipping.. Also look to see if the gas key is loose...

Gas rings not spaced right?

bullets.try a different brand.or did you and now you have this problem?that is usually whats going on.unless you have a high use weapon then it is something simple and not a "broken" AR.you could have mag spings that are worn but doubt it tho.gotta be the ammo.

Quoted: Check your extractor... Look for chipping.. Also look to see if the gas key is loose...

+1

Go ahead and put a #60 o-ring on the extractor spring just to see if it helps. At a few pennies each, you won't find a cheaper test to perform.

Quoted: Quoted: Check your extractor... Look for chipping.. Also look to see if the gas key is loose... +1

+2  extractor is my guess, damaged or something.

Work the charging handle, chambering and ejecting live rounds slowly. Look for patterns and repeated extraction failures.

Editors Note: working with live rounds is always dangerous. Be safe out there.

I had one that was doing that.

The ejector was worn where it grips the rim. That fixed mine, I then added an oring for extra insurance.

Was an Oly carbine.

Danny

Anyone use that "D-fender " super extractor?



www.fulton-armory.com/D-Fender.htm

Quoted: Anyone use that "D-fender " super extractor? www.fulton-armory.com/D-ring.jpg www.fulton-armory.com/D-Fender.htm

I use it and a Wolff extra power extractor spring together.

Gas Key is tight and staked the right way.  The bolt I got new fromw RRA shortly after getting the upper.  Extractor hu.... well the rounds are getting out of the chamber but just not out of the gun.  I will get the #60 o ring and check the extractor again.    

Quoted: I use it and a Wolff extra power extractor spring together.

Ain't that like wearing a belt and suspenders at the same time?

Urkel?

The extractor looks fine, I compared it to one I know works.

Quoted: The extractor looks fine, I compared it to one I know works.

If you have one that works start swaping parts between the 2 rifles till you solve the problem.

Quoted: Quoted: The extractor looks fine, I compared it to one I know works. If you have one that works start swaping parts between the 2 rifles till you solve the problem.

Here you have a VERY smart man.

Is the ejector moving freely?

Well I could just swap the bolts, but I did not think that was such a good idea as they kind of become fit to one gun.  Am I wrong?

Tag.

Quoted: Well I could just swap the bolts, but I did not think that was such a good idea as they kind of become fit to one gun.  Am I wrong?

Dont swap bolts.. Check  your ejector and spring.. If you use a brush to clean your bolt face, small pieces of wire from the brush can come loose and may be a problem.. Look for little tiny copper colored pieces of wire...Remove your extractor and clean underneath it. Lots of crap can accumulate.

The change in point of aim would make me curious as to the barrel slighty turning. Loose barrel nut?

problem is it is a bushmaster

Quoted: problem is it is a bushmaster

Extractor/ejector. Loss of zero sounds like a loose barrel.

Quoted: Ain't that like wearing a belt and suspenders at the same time? Urkel?

Hey, I resemble that remark!

"Also this rifle has loads of recoil; I can feel the buffer slamming the end the receiver extension every time it fires. What the heck is wrong with this thing? It shot like a dream for the last year and now it is a peace of crap. "

There's part of your problem  - WEAK buffer spring The buffer is not supposed to be
"slamming "against anything.

Quoted: problem is it is a bushmaster

http://i31.photobucket.com/albums/c361/choppersjb/notthisshitagain4jw.jpg

Take both guns to the range.

Swap upper and lower receivers.

If the problem stays with the upper, try the bolt from the other gun.  If the problem stays with the bolt... blah, blah, blah... etc, etc, etc.

(I only said "blah, blah, blah" because I dunno where you'd go from there!)  Maybe bolt from the bolt carrier, extractor from the carrier.

If it were the gas tube clogged, wouldn't that cause excess recoil?  Though, I don't know if it could get clogged at such high pressures, I don't know.

This may not be where the problem is, but I did think it was interesting. Bushmaster

This also may explain some of the questions I have read about front sights being off to one side.
HTH,
Jim

A SWAG.....with a little experience behind it. It may be your bolt is not going back far enough due to loss of gas pressure and returning to battery to quickly thus catching the brass before it clears the receiver.

I've seen this happen a couple of times on an Army range.
  One weapon had the carrier key damaged which was resulting in a loss of captured gases cycling the bolt weakly.
  The other instance was excessive gas leakage from the gas tube which required replacement of the tube.

Just something to think about.  

Quoted: Well I could just swap the bolts, but I did not think that was such a good idea as they kind of become fit to one gun.  Am I wrong?

Swap bolts, the whole wearing on one another issue is true, but also way overblown.

Quoted: Quoted: problem is it is a bushmaster hr

Yeah Bushmasters are the Sum of all Evil hate

Again I dont think this thing is short stroking as it locks back reliably.  I will try swaping uppers.  I have some people saying swaping bolts is bad some say it is ok.  The way I see it, it is a millitary firearm design and parts are ment to be interchangeable so if it the gun cant take it, it is not worth a damn.  Plus this gun no longer seems to be worth a damn anyway.  

Quoted: Again I dont think this thing is short stroking as it locks back reliably.  I will try swaping uppers.  I have some people saying swaping bolts is bad some say it is ok.  The way I see it, it is a millitary firearm design and parts are ment to be interchangeable so if it the gun cant take it, it is not worth a damn.  Plus this gun no longer seems to be worth a damn anyway.

I had the same kind of jams start on one of my RRA's almost a year and a half ago. I started checking the extractor, ejector, chamber, mags, etc. Then I had to dope slap myself because i didn't associate the problem with the collapsible stock I installed in Sept of '04. I put the A2 stock back on and bingo, no problem.  With the collapsible stock I could feel "plenty of recoil". I decided that the buffer was bouncing, so with a heavy buffer the problem went away. The gun has since fired approximately 4,500 rounds without another jam. This is just some things to consider in troubleshooting your problem.

Buffer uh...hmm

The extractor appears to be working, since the brass is extracted from the chamber. However, the brass has not been ejected from the rifle, even when the bolt locks back on the last round, the case just kind of flops and sits there on the lip of the port.



I would suspect an issue with the ejector. If you have a bolt disassembly jig or a friend to help you, carefully knock the ejector pin out and get to cleaning out the hole, spring, and ejector like there's no tomorrow. Be very careful not to lose the ejector and spring if it goes flying across the room.

I quoted instead of editted. Oopsies.

Tag for "ejector" info

pop in a new ejector spring. remember, you are dealing with EXTREMELY high pressures and velocities here. how the ejector "feels" to your finger isn't exactly the most scientific assessment. a small difference may result in a large functional difference at ungodly PSI's and when it's moving at a bazillion feet/second.

besides, new ejector springs cost, what, 18 cents?

I has this same problem in a DSA I bought awhile ago, it was the ejector.  It had a very weak spring from the factory and wasn't ejecting the brass at all.  A new stronger spring should fix.

Nic

Ok I will try and get a new ejector spring.  Any Ideas on whay my POI would change?  My rear sight is kind of screwed up but it has stayed in its same screwed up state.

I agree that there is likely a problwm with possibly the gas tubed leaking excess gas somewhere, you may need to replace that. Also possibly the ejector or extractor. Check both of those too. As for the rifle changing the POI, this could be a loose barrel nut, or possibly the FSB shifting, say if you dropped your rifle (Whcih would be an unforgivable act)? The rear sights over time do become loose, and can shift while you are shooting. It may be a good idea to check into that also. Also make sure that the chamber is clean to. If you don't have a chamber brush, i would seriously suggest getting one. One of my friends never bought one, and thought he would be fine. But after a while he had too much build up in the chamber and the rifle jammed alot.

Quoted: The extractor appears to be working, since the brass is extracted from the chamber. However, the brass has not been ejected from the rifle, even when the bolt locks back on the last round, the case just kind of flops and sits there on the lip of the port. img.photobucket.com/albums/v645/ak007/arjam2.jpg I would suspect an issue with the ejector. If you have a bolt disassembly jig or a friend to help you, carefully knock the ejector pin out and get to cleaning out the hole, spring, and ejector like there's no tomorrow. Be very careful not to lose the ejector and spring if it goes flying across the room.

A weak EXTRACTOR spring exhibits the same symptoms as pictured above. A weak extractor spring will let go of the brass too quickly, therefore not allowing it to be ejected clear of the ejection port.

Quoted: A weak EXTRACTOR spring exhibits the same symptoms as pictured above. A weak extractor spring will let go of the brass too quickly, therefore not allowing it to be ejected clear of the ejection port.

Get    replace both!

Its the Arfcom way.

Seems like looking for gas leaks and then swapping parts from the 2nd gun would be a good , inexpensive way to go.  Let us know what it was when you find out anyway.

I will be ordering some parts tonight.

Ejector spring,

Ejector pin.

Extractor spring, Wolf x-power.

Rear sight base.  (another issue not mentioned)

Any thing else.

I dont think it is a gas leak because the key is tight and the bolt always locks back on an empty mag.   I will keep yall posted.

UPDATE:
Ok I got the little guy to work again.  I think.  I only put 30rds (xm193) through it but so far so good.  I replaced the ejector spring.  The old one was very dirty.  It has some waxy skin hanging off it (CLP residue?).  I also replaced the extractor spring with a Wolf x-power unit.  The Wolf one was a little harder to put in because it was a little longer and much stronger.  I think the real problem is was with the ejector spring as it was just really messy looking.  With the few rounds I shot I noticed the brass was defiantly hitting the brass defector, because the brass was going about 45 degrees forward and to the right, 6ft from the gun when standing.  I also bought a Wolf x-power spring because I thought the bolt might have a little too much rearward velocity but I have not put it in yet.  I look forward to putting a case of wolf through this little AR again.  Thanks for the help all.

Back in service,glad to hear its working.

If your ejector and extractor springs are new and are Wolf Extra Power then they are not your problem.   I know this sounds crazy but have you cleaned an DRIED your chamber?  I had the exact same problem with one of my AR's and your pictures look exactly like what was happening with mine.  I tried everything including changing all springs and swapping out a new bolt and carrier but nothing worked.

A friend of mine asked me if I had any oil at all in the chamber.  I had given it a good cleaning before the problem and used some FP10 in the chamber.  He said the oil in the chamber was causing "increased chamber pressure".  I got every bit of oil out of the chamber and have not had any problems since.  I mean zero problems, 100% reliable and probably 2,500 rounds through is since then.

MadDog