Bolt/Magazine problems

Discussion in 'AR-15 Discussion' started by JonnyV, Jan 8, 2013.

  1. JonnyV

    JonnyV New Member

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    I've only had my freshly built AR to the range twice but each time I was having issues with rounds feeding into the chamber. Seems the bolt is just skimming over top the rounds. However, I can use the charging handle to rack them in. But then the case is ejected and the bolt skims over the next round resulting in that ever so disappointing "click". It go to the point where I could feel and hear a difference. On a few rare occasions it fed just fine. Should I be looking into a different mag? I'm just using a steel 20rd Bushmaster mag right now.
     
  2. JonM

    JonM Moderator

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    Prolly an issue with the gas system not letting enough gas through to fully cycle the bolt or a too heavy recoil spring or buffer or combination of those.

    If it doesnt lock the bolt back with an empty mag your not getting enough energy to get the bolt rearward. Doesnt sound like a magazine issue

    Saw this happen once when someone crammed a rifle length spring into a carbine buffer tube.
     

  3. JonnyV

    JonnyV New Member

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    Interesting. I did notice that the bolt seemed to be locking over the magazine after the last round instead of at the bolt catch behind the mag. I'll have to have this looked at.
     
  4. robocop10mm

    robocop10mm Lifetime Supporting Member Lifetime Supporter

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    I am betting on short cycling. Gas pressure, volume, bolt carrier group weight, buffer weight and buffer spring must me in "harmony".
     
  5. JonnyV

    JonnyV New Member

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    Alright, got a day off and decided to look into this issue. The suggestions about gas pressure/volume got me thinking. My DPMS bull barrel came with a gas block with a pic rail, it wouldn't fit under my handguard so I swapped it out. I noticed the set screws didn't line up with the divots on the barrel perfectly, but close...not close enough. When I pulled the handguard off I saw powder residue forward of the block, it was coming out from underneath it. I'm in the process of modifying the original to fit, just a little careful time with a grinder. We'll see if this works. If not, I'll look into the buffer and spring. Thanks for the help so far guys.
     
  6. Quentin

    Quentin New Member

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    Yeah sounds like you're on the right trail now. The ground down original should seal properly and solve the short stroking issue.