AR-10 not ejecting please help...with pics

fastford

fastford

Gunny Sergeant
Full Member
Minuteman
    • Sep 10, 2008
    1,492
    1
    Central, Texas
    #1
    Took my new GAP AR10 out a little while ago. It kept jamming the empty brass in the ejection hole as pictured. It occasionally would cycle 3 rounds then start jamming again. I tried 3 different kinds of ammo, two mags, and a different buffer spring all with the same outcome. Also it was beating the hell outta the brass. please help!

    FF

    photo5.jpg


    photo4.jpg


    photo3-1.jpg


    photo2-1.jpg
     
    #6
    Re: AR-10 not ejecting please help...pics

    Like AQC said. Did you put some oil in the extractor and move it up and down to make sure it isn't stuck or gunked up. I would try that.
     
    #8
    Re: AR-10 not ejecting please help...pics

    Don't assume it’s short stroking as in AR15's. AR10's can have too fast of a bolt speed, too much gas, that will act and make you believe your rifle is short stroking.

    Change the extractor and put in an extractor donut and see if that will help. If this doesn’t help there are several things that will cause you issue like you are having such as too much gas, to tight of a chamber, bad buffer spring, and so on. You need to do one thing at a time to narrow it down.

    As for beating your brass up, it's a simi-auto get use to it.
     
    #10
    Re: AR-10 not ejecting please help...pics

    Factory ammo or reloads? If reloads, try some GOOD factory ammo. Too many variables to diagnose your reloads until you know the gun functions properly.

    If factory ammo, good stuff or cheap?

    Fire ONE round with an empty mag and see if the bolt locks back, do that for 5 rounds and make sure it does it every time.

    Report back and we'll take it from there.

    An extractor donut is an O-ring that goes around your extractor spring, increasing the extractor tension. Don't ask about an ejector Twinkie, though.......
    laugh.gif


    Here's a fix you need to do to that PRS, also...
    http://www.snipershide.com/forum/ubbthre...810#Post1392810
     
    #11
    Re: AR-10 not ejecting please help...pics

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: fastford</div><div class="ubbcode-body">Ok I am dumb what is an extractor donut? </div></div>

    A little, high-stress synthetic rubber ring that slips around the extractor spring to increase extractor tension for more reliable extraction. Eliminates spring "chatter" to prevent malfunctions caused by the extractor slipping off the cartridge rim.
     
    #13
    Re: AR-10 not ejecting please help...pics

    It was bh 175's 168's fgmm 175's and supermatch 178's

    It would lock back with one round and the brass would lay on top of the empty mag and not thrown out



    Also i just puller the bolt out and 2 of the 3 gas rings where lined up, would that cause me any issues?
     
    #14
    Re: AR-10 not ejecting please help...pics

    Sounds like an ejector problem.

    Can you take a spring and ejector out of one of your other rifles and try that (you said you have other DPMS LR's)?

    Check the hole in the bolt and the spring and ejector and make sure everything slides freely inside the hole before you assemble it. I've also seen bent/mashed ejector roll pins.

    Check and make sure the ejector spring tension, when you push on it, seems the same as your other rifles.

    When assembled, hook an empty case rim under the extractor and depress the ejector plunger by straightening the cartridge, do you feel any catches? If you let go of the case, it should flip it across the room.

    PS
    On your edit, if it was reliably locking the bolt back with single rounds; then no, it shouldn't have been a problem.

    PPS
    Was the empty laying on the mag pointed forward or back?
     
    #16
    Re: AR-10 not ejecting please help...pics

    Another thing, you do realize the difference in an AR10 (made by Armalite) and the DPMS LR pattern gun you have in the pic??

    What you are showing in the pic is NOT an AR10.

    The bolt parts may not be interchangeable.
     
    #17
    Re: AR-10 not ejecting please help...pics

    I just took an empty case and hooked it in a new bolt and pushed it into position on a weight scale (pushing the scale down with the mouth of the case)and it took about 3.5-4 pounds to push the ejector all the way down.

    If it's much lighter or heavier than that, you need a new spring or something is binding up.
     
    #19
    Re: AR-10 not ejecting please help...pics

    Also i just puller the bolt out and 2 of the 3 gas rings where lined up, would that cause me any issues?

    I will probably be ostracized for this, but I think gas ring alignment is a myth...
    shocked.gif
     
    #20
    Re: AR-10 not ejecting please help...pics

    i had that same problem with an ar15.
    i switched uppers from a midlenth to a carbine length upper and it started doing that. so i assumed it was the upper.
    it ended up being the buffer. it was too light. the bolt was flying back too fast not being slowed down by the buffer fast enough. the ejector was loosing its grip and the round would spin in the gun like that.
     
    #21
    Re: AR-10 not ejecting please help...pics

    i thought it was an ejector at first and put the bcm upgrade extractor but that didnt change anything. the bolt was flying back so fast it would actually rip or bend the extracer lip on the case head. look at your brass where the ejector grips them. are they all messed up?
     
    #23
    Re: AR-10 not ejecting please help...pics

    I had the same problem with my DPMS SASS.

    1. Most importantly, the problem with your rifle is that it is WAY over gassed. This is because AR-10 / DPMS 308 barrels have the MAXIMUM size gas port drilled in them. It's a great mass production idea to insure a filthy rifle will cycle, but at the brass tacks level it causes a heck of a lot more problems than it solves.

    Mine was so bad, I had to have a custom gas block built so I could <span style="font-weight: bold"><span style="font-style: italic">regulate the gas down to a reasonable amount.</span></span>

    2. If the gas key sticks at all / the least little bit on the gas tube, then that will also cause problems.

    3. If you can <span style="font-weight: bold"><span style="font-style: italic">push in</span></span> the ejector with your fingernail, the spring is too weak. The ejector spring on an AR-10 / DPMS 308 needs to be very stiff in order to work correctly.

    My gunsmith (Jense Precision) got these answers by calling DPMS and finally being referred to a long time AR-10/DPMS 308 builder and in-house expert.

    Best of luck.
     
    #24
    Re: AR-10 not ejecting please help...pics

    If the case was laying backwards it may not be your ejector, it may be back to something more complicated, like a gas issue.

    Do the easy stuff first.....

    I'd try putting in a different ejector and extractor (with springs) first, it's simple.

    Compare your buffer (weight and length) to one of your other guns, also.

    Check your bolt stop overrun, your buffer may be the wrong length, explained here......
    http://www.snipershide.com/forum/ubbthre...200#Post1986200

    If none of those things fix it, I'd send it back to GAP.
     
    #25
    Re: AR-10 not ejecting please help...pics

    Looks like overgas to me. I can't make out the shell deflector that well to see brass marks. The D shaped necks lead me to believe that its ejecting the brass rotates out and wacks the shell deflector hard it enough to bounce back in and get caught up in feed cycle. Don't think its under gassed as its picking up the new round and passing single round test. As a reloader and one who likes my brass to stay nice and round I always put the loop side of velco on my shell deflector to act as a port buffer to keep my brass from getting beat up. Also seems to help with overgassing as it softens the impact of the brass on the deflector. You can do a poor mans adjustable gas block by loosing the screws and slightly misalign it to reduce gas volume. Or just try some lower pressure 308 ammo and see if that helps. My AR10 likes to run with a heavy bolt/buffer (tubbs Carrier Weight System)
     
    #28
    Re: AR-10 not ejecting please help...with pics

    Interesting. Considering cutting mine down to 20". I've been worried about "overgassing" with a 26" Kreiger but not a single cycling problem as of yet (250rds) (not meaning to rub it in - don't worry, i got my own problems).

    Re: "Overgas" - I've read other guys who had this problem compare the size of their gas port in the barrel with others and figure out real quick if it is too big (fix was an adjustable gas block). The gas port in my 26" is pretty small.
     
    #29
    Re: AR-10 not ejecting please help...with pics

    I have seen this problem on numerous rifles while tuning in the gas system. As mentioned above, it's almost certainly either overgassed or your ejector is too weak. What happens is that the bolt moves to the rear so fast that the ejector doesn't have time to spin out the case. Then only the top half of the case is out of the ejection port when it hits the deflector, causing the case to bounce around and end up right where it did in your pic. Sometimes it also spins 180 like you mentioned. I have a bunch of high speed vid of this happening but nothing I can post.

    In some rare cases a failing extractor has caused that type of failure. Try to get ahold of a spring out of an LWRC REPR, but really you'll probably need an adjustable gas block.

    Anyway, it's an easy diagnosis: 1. Replace Extractor and spring, 2. Replace ejector spring, then as a last resort, adjustable gas block

    Good luck,
    Justin
     
    #30
    Re: AR-10 not ejecting please help...with pics

    I'm surprised that only one person, (Hellbender) suggested sending it back to GAP. I can understand that probably after waiting awhile for the rifle, you might be reluctant to send it back if this could be a simple fix, but if it were me, I'd at least contact GAP and discuss the issues.

    IMO, you're paying a premium for a professionally built rifle which should run out of the box vs. saving a little and building one yourself and having to deal with any issues on your own. Even if the fix could be something as cheap and simple as a new extractor and/or spring, etc, for me, having to take the time to troubleshoot, ammo, along with more possible frustration is not cheap. Like I said, that's what you paid the builder to do and given GAP's reputation, I'm sure they'll take care of it, no problem. I don't see you having to spend any money out of your pocket to make the rifle function.
     
    #31
    Re: AR-10 not ejecting please help...with pics

    +1 to overgass. I've seen the exact same thing before and some people fixed it with insane extractor tension. (Not really that good of a fix if you ask me.) Adjusting the gas down a bit and possibly using a heavier buffer could help.

    I'd be on the horn to GAP.

    Side note:
    What kind of lube are you using? It looks thin and strange. I've never had any luck with any lube besides Breakfree CLP in AR pattern rifles. I had a buddy's AR-10 run shitty until I convinced him to use CLP. Something to consider.
     
    #33
    Re: AR-10 not ejecting please help...with pics

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Nihonjin</div><div class="ubbcode-body">I'm surprised that only one person, (Hellbender) suggested sending it back to GAP. I can understand that probably after waiting awhile for the rifle, you might be reluctant to send it back if this could be a simple fix, but if it were me, I'd at least contact GAP and discuss the issues.

    IMO, you're paying a premium for a professionally built rifle which should run out of the box vs. saving a little and building one yourself and having to deal with any issues on your own. Even if the fix could be something as cheap and simple as a new extractor and/or spring, etc, for me, having to take the time to troubleshoot, ammo, along with more possible frustration is not cheap. Like I said, that's what you paid the builder to do and given GAP's reputation, I'm sure they'll take care of it, no problem. I don't see you having to spend any money out of your pocket to make the rifle function. </div></div>


    This started yesterday afternoon, GA was closed. I will call them monday, I was just tryin to get it licked before then
     
    #35
    Re: AR-10 not ejecting please help...with pics

    Gap always test fires their rifles before they send them out, did you buy the complete rifle or just the upper? I use the endine buffer with my supressed Gap, it does a good job.
     
    #36
    Re: AR-10 not ejecting please help...with pics

    Port pressures can vary significantly with different ammo (GAP's test ammo compared to OP's ammo for example), coupled with the fact that an overgassed gun will often run ok for any given string of shots, it's not a big surprise that it could make it out of GAP in this condition. To really make sure a gun is functioning properly you would have to put it on the high speed vid before you shipped it, which is a serious proposition even for a basic camera setup, when you have many rifles going out.

    The reason to fix it yourself would be time saved, and first hand knowledge gained. If you bought a the new parts mentioned, you could then experiment with different configurations to gain some new insight to the function of a rifle. And it's fun.
     
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