1. Sign up now and join over 35,000 northwest gun owners. It's quick, easy, and 100% free!
  2. We're giving away over $1,000 in prizes this month in the Northwest Firearms Winter Giveaway!
    Dismiss Notice

7.62x39 Bushmaster upper not consistently firing

Discussion in 'Rifle Discussion' started by Remadl700, Dec 25, 2011.

  1. Remadl700

    Remadl700 Oregon Member

    Likes Received:
    My bad on the upper make!!! I was told it was an Oly.

    We put this brand new upper on my BM lower and it won't consistently fire the rounds. We used two types of ammo and changed the firing pins out. Also placed the 223 upper back on and had no problems with 223 ammo or firing pin. The pins look to be cratering the primer fairly well.

    .??????? :huh:

    12-27 : went to Hornady ammo and a JP enterprises spring kit.
    Result : same issue FTF on 4 different types of ammo

    The purpose to buying this is to have platform that can reliably fire 7.62x39 ammo without having a different weapon......

    Update 2: put in the Heavy Hammer spring and milled a couple thousands from the shoulder of the firing pin. Not one FTF! In 60 rounds plus 2 more mags on the Slide Fire stock .......in the Rock And Roll setting :)
  2. nubus

    nubus Guest

    Are you using the heavier hammer spring and the 7.62x39 firing pin? If you are using steel cased ammo (wolf, etc.) good luck.
    I have had poor luck with steel ammo in AR-15s regardless of manufacture, hard primers and stuck cases repeatedly.
    Just my personal experience, but the hammer spring can make all the difference.
    Nwcid and (deleted member) like this.
  3. eldbillbo

    eldbillbo clackamas New world samurai and a redneck none the less Bronze Supporter

    Likes Received:
    its feeding right? just light primer strikes? or?
  4. Eric911

    Eric911 WA Member

    Likes Received:
  5. Remadl700

    Remadl700 Oregon Member

    Likes Received:
    Thank you!

    My bad it is a Bushmaster. I was told it was an Oly and did pay it any more attention.....Piss poor excuse but it's all I have got right now.