G&P M4 Problem

Discussion in 'Gun Building, Modifications & Repairs' started by SD1014x, Oct 28, 2012.

  1. SD1014x

    SD1014x New Member

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    Yesterday I was shooting on full auto with my G&P M4 when there was a jam, and the gun stopped shooting. It then made a whirring noise for a couple of seconds every time I pulled the trigger. I cleared the jam, but it still won't shoot. If I look down the magwell I can see a silver metal piece that goes back and forth with each "whir". My friend said it's probably the o-ring in the air nozzle, but I want to be sure. I saw similar threads where it looked like the piston was stripped, but my M4 is 3 months old with only 3-4000 rounds through it. Any advice is appreciated, thanks
     
  2. andrew72700

    andrew72700 New Member

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    My gun did the same and it was a stripped piston
     

  3. marine121496

    marine121496 Wahahaha~ Supporting Member

    7,506
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    Ann Arbor
    Happened to my friends G&P m4, and his was only 2 months old, very possible it happened to yours.
     
  4. SD1014x

    SD1014x New Member

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    A stripped piston? (20char)
     
  5. 1badweasel

    1badweasel New Member

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    Santa Rosa
    I believe it means the teeth on the piston are stripped.
     
  6. alex

    alex New Member

    4,794
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    Atlanta
    the nozzle is the part moving in and out inside the feed tube. usually, when one upgrades to a higher discharge battery without correcting AOE, the stock piston will crack at the the pickup end. i'm going to assume there is no longer any air pressure coming out of the barrel. you will need to open up the gearbox to fix/repair the damage.
     
  7. EDI1st

    EDI1st New Member

    2,062
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    Fountain Valley
    Or stripped gears, it's a G&P, who knows what actually happened? :p

    Open it up and find out.