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AR15 Not Feeding, Only Ejects Sometimes

Discussion in 'Maintenance & Gunsmithing' started by cascadianliberty2012, Apr 12, 2014.

  1. cascadianliberty2012

    cascadianliberty2012 DPR Portland Well-Known Member

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    I built my first AR15 a couple months ago and have put about 50 rounds through it by now. Today I finally got my scope for it and went to sight it in. I shot about 6 rounds for groups at 25 & 50yds to make sure I was shooting consistently. However, then it all of a sudden stopped feeding and the bolt was noticeably not being thrown back far enough to catch the next round from the magazine. I tried different magazines and different ammo and got the same result. Next, I removed most of the oil that I had in the chamber (which was excessive), took the BCG apart entirely to de-oil/gunk it, then removed the gas block (which was actually wiggling slightly) and found that it looked like gas had been escaping around the barrel as there was a lot of carbon buildup all around the area. I cleaned the outside and chamber end of the gas tube, then resecured the gas block with some locktite, and proceeded to try again. No luck. Now it even jams and only ejects sometimes...

    Does anyone have any idea what else I could try to get this to work? If it helps, my BCG is Spike's Tactical. This is frustrating for me, especially since it worked so great before...

    Thanks!
     
  2. bellarum

    bellarum beaverton Well-Known Member

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    Check the gas key. It might be loose or your gas block could be misaligned.
     
    mjbskwim and ZA_Survivalist like this.
  3. ZA_Survivalist

    ZA_Survivalist Oregon AK's all day.

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    Also, what buffer are you running as well as your gas tube length and the type of ammo?

    Sometimes with a longer barrel
    20"+ the cheaper wolf/Tula has a hard time running and wont cycle the BCG..

    but it seems to work flawlessly in shorter (16" & down) barrels.
     
  4. Garg

    Garg east of portland metro Hold my beer..... watch this Bronze Supporter

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    Sounds like you still have a gas block/gas tube alignment issue.
    I personally do not recommend loctite on gas blocks, as they can be a bear to get off.
     
  5. cascadianliberty2012

    cascadianliberty2012 DPR Portland Well-Known Member

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    I hear the gas blocks with locktite aren't that bad to get off, so long as you don't use the most extreme level.

    I've been using PMC, Independence, and Remington ammo. None of it makes a difference.

    My AR15 is carbine length.

    I'll do some more checking of the gas key and gas tube. I suppose it might be possible it has a partial blockage in it or something. Does anyone have a good method of how to clean these out?
     
  6. SCARed

    SCARed Vancouver, WA Well-Known Member

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    Gas block not on correctly, too loose.
     
  7. cascadianliberty2012

    cascadianliberty2012 DPR Portland Well-Known Member

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    I've got that block cinched down real good, but it still isn't cycling. I'm getting real confused.
     
  8. Reno911

    Reno911 Hillsboro Well-Known Member 2015 Volunteer 2016 Volunteer

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    Is you block actually aligned with the gas port on the barrel?

    Did the block shift while shooting the first rounds and you adjusted and tightened?

    Is your gas tube pinned properly to your gas block?

    Your gun is short cycling. If it cycled before chances are something to do with the gas portion of the gun is off line or damaged.

    That or you switched to steel cased ammo.
     
  9. cascadianliberty2012

    cascadianliberty2012 DPR Portland Well-Known Member

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    It may have shifted over my first 100 shots or so, when I went to check the screws, one of the 4 was loose and it did have a very minute amount of horizontal play in it, but it still seemed like it should've been within the acceptable range.

    As far as I know the tube is attached properly as it is secured in there and isn't movable.

    And yeah, I know better than to put steel cased ammo through an AR :)
     
  10. ZA_Survivalist

    ZA_Survivalist Oregon AK's all day.

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    Hey now, if a rifle cant shoot all types of cased ammo.. Its not a good rifle. ;)
    And Ill stand by that.

    In one of my ARs, its diet is almost all steel. :) I think the last round count was 7-875ish? All el cheapo tula. (Terrific practice ammo)

    Dont let those guys at ARFcom fool you. LoL.
     
  11. HappyRoman

    HappyRoman Sherwood Forest Bronze Supporter Bronze Supporter

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    A new AR needs to be broke-in.. usually run a patch thru 3-5 rds first 25 rd, then every 10 rounds till 100.
    Clean the chamber, bolt and all..Solvents, air, and wipe out well or use a brush for loose powder and residues. Now ,I would disassemble the lower, flush with a clearer, blow dry vigorously, and try blowing the gas tube to verify unplug or un-plug it. They make long pipe cleaners for that. Lubricate reassembly and retest. When reassembling remember the above cements on the bolt carrier and all the other stuff, and verify firing pin is intact.
     
  12. cascadianliberty2012

    cascadianliberty2012 DPR Portland Well-Known Member

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    I've always stuck to the rule of not putting steel in American semi-autos. Just following Moh's scale of hardness on that one :cool:
     
  13. ZA_Survivalist

    ZA_Survivalist Oregon AK's all day.

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    LoL..
    I suppose its just the AK fanatic in me that forces me to abuse my toys.
    Always a steady diet of steel.

    But really though no issues with any steel cased ammo.
    Hope your gas system issues get resolved.
    Any pictures?
     
  14. cascadianliberty2012

    cascadianliberty2012 DPR Portland Well-Known Member

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    I'm definitely way more of an AK guy than AR. I keep telling myself "this is why I own an AK," and "I'm glad I invested so much in my AK," along with other variations of such sentiment which includes hating .223 and being glad that my AK is in .308 lol. This AR is more of a project, as it is the result of an 80% build. I'd post pictures of it on here, but there is a wee bit of anti-NWO profanity on it that the moderators would probably despise. Would a picture of the gas block or anything be of use?
     
  15. Reno911

    Reno911 Hillsboro Well-Known Member 2015 Volunteer 2016 Volunteer

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    If you put on the gas block may be worth taking it off. Measuring the port on the block. Measuring the port on the barrel. Mark centers. Then reinstall using your measurements. Or have a gunsmith perform the task with aid of a bore scope.

    Most short strokes are caused by three things.

    Steel cased ammo. It is usually less powerful than other ammo. No there really isn't much harm in shooting it either unless your into 10s of thousands of rounds.

    Buffer being to heavy. If built using a run of the mil parts kit chances are this is not the problem.

    Gas system problem. This the third and most fun one can be many things. Basically your not feeding enough gas to push the bolt back. Pressure is getting lost or not enough is getting in. There are a few parts related to this system. The gas key on your BCG. Make sure there is nothing in it blocking gas from getting in. Gas rings, make sure they are on your bolt. Gas tube, make sure it is pinned to the gas block and that the gas key fits snugly around it. If you can't tell remove your gas block with tube and bolt from the gun and do this outside of the gun. Gas block, is not aligned with the port in the barrel. Or the port on the barrel is too small. Some lesser expensive barrels make this mistake. Off the top of my head I can't recall the dims, but googling it may help. Mid length is different from rifle and so forth. Usually the port on the gas block is not an issue of size as most are bigger on purpose.

    That's all I got.
     
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  16. ZA_Survivalist

    ZA_Survivalist Oregon AK's all day.

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    Yeah, the gas block type and location in relation to the gas port?
    .308 AK you say?!
    Saiga, Vepr, Galil, Yugo?
    I myself was and still am a Saiga .308 fanatic.. But the Yugo M77 really caught my eye as of late.
     
  17. Garg

    Garg east of portland metro Hold my beer..... watch this Bronze Supporter

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  18. cascadianliberty2012

    cascadianliberty2012 DPR Portland Well-Known Member

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    Yes it is! A .308 Saiga, shorter barrel, fully converted with a Nikon 2-7 on it (I want it to have closer abilities), and a G2 trigger. Shoots beautifully. This AR is really just a supplemental rifle.

    Here's what the block looks like. It is covering the port.

    20140413_234015.jpg

    20140413_233946.jpg

    20140413_233936.jpg
     
  19. HappyRoman

    HappyRoman Sherwood Forest Bronze Supporter Bronze Supporter

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    Come on guy's, he's asking for ideas and help, not to be ridiculed or that your guns are better. Technical support is what's needed.. I think.. my .02c
     
  20. Garg

    Garg east of portland metro Hold my beer..... watch this Bronze Supporter

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    Try removing the hand guards, and realigning the block. If the block came loose, the spring tension on the delta ring could have pushed the whole assembly forward, continuing to partially block the gas port.

    And to Happy, we are trying to help. No one is ridiculing him.
     
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