New AR pistol build with a few hicups, help?

Discussion in 'AR-15 Discussion' started by truevil1313, May 29, 2014.

  1. truevil1313

    truevil1313 New Member

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    I built an all new AR pistol chambered in 300 AAC BLK. I used all new parts. The barrel is from AAC and is 9 inches with a pistol gas system. I used the H2 buffer that AAC says I should use.
    I took it out today and fired 30 rounds only. I had 1 double feed, and twice the bolt did not go fully into battery. It like got stuck, it would not go forward or come back out. Anybody have any idea what might be going on? Is it just because it is all new and needs some break in time, or is there a problem?
    I was using new 150 grain supersonic rounds.
     
  2. Sniper03

    Sniper03 Supporting Member

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    truevil,

    Are these reloads or someones loads? To start with it sounds simply like an ammunition problem not having the proper dimension! We will start with that!

    03
     

  3. SSGN_Doc

    SSGN_Doc New Member

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    Don't know how many builds you have done. Ammo would be a likely place to start, but another possibility is gas block placement. If the gas block is seated all the way to the rear of the shelf in the barrel, it could under gas a bit and can cause some gas tube binding as well.
     
  4. truevil1313

    truevil1313 New Member

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    These are reloads from Freedom Munitions. I have used a lot of their ammo in the past and never had any problem with it, but this is the first time I have tried their 300 BLK ammo.
     
  5. truevil1313

    truevil1313 New Member

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    This is my first ground up build, but I have replaced lots of parts including gas blocks on my other ARs.
    With the AAC barrel and gas block, it seems rather difficult to not get the alignment correct, because the gas block is pinned in place. The barrel has a cutout that the pin goes through and lines everything up.
     
  6. purehavoc

    purehavoc New Member

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    Try a lighter buffer for starters and see what happens
     
  7. Argyle_Armoring

    Argyle_Armoring New Member

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    Make sure your buffer tube isn't screwed on one rotation too many. If it is it'll cause your BCG to short stroke. Your buffer tube should barely hold in the buffer retaining pin at the very edge.
     
  8. truevil1313

    truevil1313 New Member

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    Thanks everyone, I will check these things when I get home.
     
  9. truevil1313

    truevil1313 New Member

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    OK o I checked, my buffer tube was too far in. I made that adjustment, and everything seems to be smother. I was able to cycle two mags worth of ammo through it by had. I hope to get back out this weekend and see for sure this fixed it, but as far as I can tell right now, I think it did. I never knew it was that critical.
     
  10. Copeman60

    Copeman60 New Member

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    Show us a picture of your 300BLK pistol build!!
     
  11. truevil1313

    truevil1313 New Member

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    Here it is.
     

    Attached Files:

  12. truevil1313

    truevil1313 New Member

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    It is a Texas Black Rifle Company lower, CMMG lower parts kits, PSA pistol buffer tube, Sig SB15 brace, Giselie fast fire trigger, Houge pistol grip, carbine buffer spring, H2 buffer, SAA billet upper, unknown upper parts kit, AAC 9 inch barrel with pistol gas system and gas block, YHM free float 9.2 inch hand guard, AAC flash hider/suppressor mount, and a Vortex Sparc II red dot.
     
  13. seancslaughter

    seancslaughter New Member

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    Ha I'm gonna stop by Texas black rifle today on my way out to flatonia I've been dying to check it out


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  14. truevil1313

    truevil1313 New Member

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    I hope you know, that you have to go to Shield Tactical in Shiner. They are sister companies I guess.
     
  15. seancslaughter

    seancslaughter New Member

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    Yeah that's where I went just leaving now what an awesome group of guys


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  16. seancslaughter

    seancslaughter New Member

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    They just finished another batch of those 1836 lowers sending them off to get anodized so they should be back in 2 weeks or so


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  17. truevil1313

    truevil1313 New Member

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    That is great! I love those guys! I found them on Facebook and just knew they were cut from the same cloth that I am.
    My wife bought me number 15 of the first 200 they had made, and that is what I built this pistol out of, until I get my tax stamp back from the ATF. Then it will be a SBR.
    Update!!! It was the buffer tube! I backed it off a little bit today, and I was able to put another 50 rounds through it today without a hiccup! It seems all is well now! Damn I love the 300 BLK.
     
  18. seancslaughter

    seancslaughter New Member

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    I think I'm gonna pick up a lower in 2 weeks and build it into a 458 socom to do some pig slaying at the in laws farm they are rooting real bad and messing up the hay. Does yours have the cmc trigger? One of the guys let me check his rifle out and that trigger was awesome.


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  19. FAS1

    FAS1 New Member

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    Nice! Could you give me some dimensions please? I am interested in the OAL with the brace and the OAH from the top of the sight to the bottom of the mag.

    Thanks in advance.
     
  20. Sgt_Skrb_25

    Sgt_Skrb_25 New Member

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    Pure, I just recently had the same issues with my pistol. Coincidently ever since I put on my SigTac SB15 I've had cycling issues. I rebuilt it from the ground up and tried 4 different buffer weights and still have issues. I have to check my buffer tube now. It's the only thing I didn't check. I don't know anything else to check. It's had 1k plus through it with out issues, but since I put the SB15 on it all went to crap. I did put a new tube on, Thanks for the idea.


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