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General Categories => General Firearm Discussion => Topic started by: maanbr on August 12, 2009, 12:08:40 AM

Title: AR15 jam
Post by: maanbr on August 12, 2009, 12:08:40 AM
Had this one occur in an AR15 a few weeks ago.  The ejecting brass got stuck above the bolt after firing.  Any idea what would cause this.  Been firing these weapons for 12yrs now and have never seen it.  Got it cleared by pushing a screwdriver against the bolt face/carrier to the rear.  Pulling the charging handle just makes it worse.

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Title: Re: AR15 jam
Post by: AAllen on August 12, 2009, 09:03:59 AM
Seen one like that once back in the military, extractor spring was weak and the extractor was extreamly dirty and not able to freely move.  We removed the extractor cleaned it and it's seating area and replaced the spring and it worked fine after that.
Title: Re: AR15 jam
Post by: maanbr on August 12, 2009, 10:13:54 AM
The weapon was clean, and I fired a couple more mags after I cleared it without a problem.
Title: Re: AR15 jam
Post by: FarmerRick on August 12, 2009, 11:48:05 AM
I've heard(on AR15.com) about that happening, but never seen it myself.  I'd search there for possible causes and solutions.
Title: Re: AR15 jam
Post by: Dan W on August 12, 2009, 10:35:15 PM
I am guessing something like the extractor loses it's grip on the case just before the neck  clears the chamber. The fired  case has enough inertia to continue to the rear, when the neck hits the edge of the chamber, and forces the base of the spent case to go high in the rear, and it holds there just long enough for the bolt to move back toward battery, where the cussing begins, as the bolt wedges the base  above the bolt
Title: Re: AR15 jam
Post by: RobertH on August 12, 2009, 10:58:41 PM
were you shooting pretty rapidly?

in a somewhat unrelated case, my Ruger MKIII (22LR) will sometimes not eject the old casing when i shoot it really fast.  but thats a pistol and smaller cartridge.
Title: Re: AR15 jam
Post by: maanbr on August 13, 2009, 12:38:46 AM
No, not rapid firing.  Just a standard paced target shooting rate of fire.
I was thinking more along the lines of what Dan had posted.  Just wondering if anybody else had seen this malfunction and what the cause was.
Title: Re: AR15 jam
Post by: Rich B on August 13, 2009, 08:17:15 AM
What kind of extractor setup do you have?  XP spring?  Black or blue insert?  O-ring or D-fender present?  How many rounds on the extractor and spring?
Title: Re: AR15 jam
Post by: f1fanatic on August 16, 2009, 11:42:52 AM
My guess is a fouled ejector. Possibly a weak spring. My RRA never came with an O-ring and hasn't had any problems but I'm thinking of installing one anyway with an upgraded spring.
Title: Re: AR15 jam
Post by: JimP on August 17, 2009, 10:58:38 PM
If it ain't broke......
Title: Re: AR15 jam
Post by: semtex on August 18, 2009, 10:52:00 PM
Fix it before it breaks. Especially if you want to use that weapon for anything but "target practice."
http://www.bravocompanyusa.com/BCM-Extractor-Spring-Uprade-Kit-p/bcm%20extractor%20spring%20upgrade.htm (http://www.bravocompanyusa.com/BCM-Extractor-Spring-Uprade-Kit-p/bcm%20extractor%20spring%20upgrade.htm)
Title: Re: AR15 jam
Post by: semtex on August 18, 2009, 11:10:05 PM
OP, a simple test to see if it is a gas system issue is:
Load one round in the mag. Fire. Did the bolt lock back? If not you probably have a gas problem.

Also Check:
- FSB for wobble
- Gas tube for propper fit and deformities
- Gas rings on bolt
- Carrier key: screws tight and staked? And loosness in carrier key?

If the gas system is good to go, then I would look at the ejection systems.
Title: Re: AR15 jam
Post by: SeanN on September 02, 2009, 07:13:44 PM
Any updates on this? Has the problem occured again?
Title: Re: AR15 jam
Post by: maanbr on September 03, 2009, 10:56:12 PM
Haven't fired it lately, but the few mags I ran through it after the jam had no problems.  I honestly think it was just one of those random jams.  I was just wondering the cause of it and how many others had seen the same type of one as I hadn't in 12yrs of shooting AR's/M16's.
Title: Re: AR15 jam
Post by: SeanN on September 03, 2009, 11:28:37 PM
Glad it seems to have fixed itself. I would suggest, if it happens again, you do what one of the other members suggested and make sure your extractor spring and o-ring are strong enough and if not purchase Bravo company's 'extractor upgrade'. They make great parts.
Title: Re: AR15 jam
Post by: AAllen on September 04, 2009, 08:36:23 AM
With the fact that it has not happened again after firing several more Mags through it my guess is you are right it's just one of those random things that happen, may have been the extractor did not grab correctly, could have been a light load could have been a lot of things but it does not appear to be anything is wrong with the rifle.
Title: Re: AR15 jam
Post by: SeanN on September 04, 2009, 08:39:16 AM
With the fact that it has not happened again after firing several more Mags through it my guess is you are right it's just one of those random things that happen, may have been the extractor did not grab correctly, could have been a light load could have been a lot of things but it does not appear to be anything is wrong with the rifle.

Yeah that's definitely a possibility. What kind of ammo was it? If it was Wolf or one or the cheaper brands I wouldn't be surprised at all. (No offense to those that shoot wolf but it is one of the lower rung ammos)
Title: Re: AR15 jam
Post by: maanbr on September 05, 2009, 12:53:56 PM
It was Fed. American Eagle 55gr FMJ.
Thanks for the answers.