AR pistol 7.5" problem.

Discussion in 'Maintenance & Gunsmithing' started by biggie24420, Jul 14, 2017.

  1. gryghin

    gryghin
    Beaverton
    Gold Supporter Gold Supporter

    Messages:
    381
    Likes Received:
    352
    Have you verified that the pistol upper is not suspect by using it on a different pistol lower, with all the associated BCGs and buffers that exhibited the problem on the Aero lower?

    If you don't have one available, I'd be willing to meet up at Wolf Creek Road, so that a proper test could be done.
     
  2. Reco

    Reco
    Portland Oregon
    Active Member

    Messages:
    373
    Likes Received:
    78
  3. 308

    308
    ΜOΛΩΝ ΛΑΒΕ
    ΜOΛΩΝ ΛΑΒΕ

    Messages:
    5,266
    Likes Received:
    14,566
    If it is short stroking, he can open the gas port a bit. I did that with my shorty FAL several years ago and it ran perfect afterwards.
     
    biggie24420 and Velzey like this.
  4. biggie24420

    biggie24420
    Beaverton Oregon
    Well-Known Member

    Messages:
    1,763
    Likes Received:
    666
    No I haven't done that. The only other lower I have is my M4 lower and that'd obviously be a no no. I appreciate the offer but I'm gonna wait till I install the new catch and go shoot it. I will PM you if I decide to take you up in that offer.
    Thank you!
     
    Last edited: Jul 16, 2017
    gryghin likes this.
  5. biggie24420

    biggie24420
    Beaverton Oregon
    Well-Known Member

    Messages:
    1,763
    Likes Received:
    666
    That was one of my earlier thoughts but shooting my M4 16" upper on that pistol lower, same issue with the BCG, wouldn't lock back. That threw me off a bit but I like the pistol so one way or another...... I'll get to the bottom of this.
     
    gryghin likes this.
  6. Kruejl

    Kruejl
    Hillsboro
    Moderator of the Coriolis effect Staff Member Gold Supporter

    Messages:
    5,373
    Likes Received:
    13,922
    Try a lighter buffer spring.
     
    Velzey likes this.
  7. biggie24420

    biggie24420
    Beaverton Oregon
    Well-Known Member

    Messages:
    1,763
    Likes Received:
    666
    The original carbine spring from the Stag M4 was used originally. That spring is the lightest out of the 4 springs I have. I've used the one out of my spikes M4, the Stag spring (one I just mentioned), and my new Wolff and Colt..... same result, no BCG lock back after last round.
     
  8. Garg

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

    Messages:
    1,382
    Likes Received:
    1,635
    It's gotta be that dang fancy bolt catch. Replace that then check back in with us.
     
    gryghin and Stomper like this.
  9. biggie24420

    biggie24420
    Beaverton Oregon
    Well-Known Member

    Messages:
    1,763
    Likes Received:
    666
    Ya my package from MidwayUSA will be here on the 25th and I plan on taking the GF shooting on her birthday next month so That's when I'll be testing the new catch lever.

    Unless I find a private property to go shoot a few rounds on, I'll have to wait a while. Every time I go to the range, it's $30 or so...... it's getting old lol. Ya I could go to the woods but my car doesn't like to go off road..
     
  10. Stomper

    Stomper
    SCREW YOU SALEM!!
    SCREW YOU SALEM! Gold Supporter

    Messages:
    18,223
    Likes Received:
    42,181
    You need one of these babies!

    IMG_4403.GIF
     
    biggie24420 likes this.
  11. Garg

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

    Messages:
    1,382
    Likes Received:
    1,635
    Well, you are welcome to come out to my place, and test it here. We could tech that thing just right, test the bolt catch, change it out, test different uppers, lowers, what ever you want, and I wont charge you $30. I am on the other side of the world though lol....out towards Estacada...
     
    biggie24420 likes this.
  12. Mygrainman

    Mygrainman
    SW WA
    Bronze Supporter Bronze Supporter

    Messages:
    1,350
    Likes Received:
    4,261
    Does it have one of those "pig tail" gas tubes? I've heard of those causing short stroke issues.
     
  13. biggie24420

    biggie24420
    Beaverton Oregon
    Well-Known Member

    Messages:
    1,763
    Likes Received:
    666
    No it's a pistol length gas tube. It's even shorter than the M4 gas tube.....it's kinda cute and adorable lol. I wanna replace it with a melonite coated gas tube eventually.
     
  14. biggie24420

    biggie24420
    Beaverton Oregon
    Well-Known Member

    Messages:
    1,763
    Likes Received:
    666
    Hey folks.... (yuk I sound like Obama lol).... went shooting yesterday to test the AR pistol. So I got my Colt BCG release and a new Strike Industries dust cover (since I cut up my metal dust cover).

    So I chambered one round and pulled the trigger...... the BCG locked back after the round was fired! I was so excited and relieved. :)


    Now... when I removed that fancy shmancy ambi bolt release, obviously it was a bigger part and compared to the normal bolt release, it's almost twice as heavy (I didn't weight it with a scale) and it probably couldn't move into place fast enough to hold the BCG back on the last round. But if you manually tired to lock the BCG back with an empty mag, all wold seem normal. So several times I loaded a mag with one round and I got a BCG lock back after every round.

    Overall it was a quick fix, my brass is ejecting at 3 o'clock position...... no issues with feeding or ejecting. I do want to shoot some steel case ammo and see how it handles it. I love the Strike Industries dust cover, so easy to install and it fits great.

    Thanks you all for your help and input and offers to help me out. I hope this thread helps others in the future.

    AR1.jpg AR2.jpg AR3.jpg
     
    Caveman Jim, gryghin and 308 like this.
  15. 308

    308
    ΜOΛΩΝ ΛΑΒΕ
    ΜOΛΩΝ ΛΑΒΕ

    Messages:
    5,266
    Likes Received:
    14,566
    Those KNS retainers are a nice touch too.
     
    biggie24420 likes this.
  16. Garg

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

    Messages:
    1,382
    Likes Received:
    1,635
    On pistol AR's they are almost essential. Those things rattle around like nothing else LOL...
     
    Diamondback likes this.
  17. Diamondback

    Diamondback
    Crapper Gunsmith
    Well-Known Member

    Messages:
    5,095
    Likes Received:
    10,408
    Good to know--I personally won't do a poly lower without 'em for structural-strength reasons, and with the current build being a poly-lower pistol that's gonna be a double-whammy.
     
  18. 308

    308
    ΜOΛΩΝ ΛΑΒΕ
    ΜOΛΩΝ ΛΑΒΕ

    Messages:
    5,266
    Likes Received:
    14,566
    They are an absolute must for the M&P 15/22 since the pins walk out and next thing you know it's double tapping.
     

Share This Page