BCM bolt carrier group

Discussion in 'AR-15 Discussion' started by louieboots, Jun 30, 2012.

  1. louieboots

    louieboots New Member

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    I bought a BCM bolt carrier group and it came with a small nut or something I'm not sure what it's for can anyone tell me? I'm new to the AR platform..
     
  2. Quentin

    Quentin New Member

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    O-ring? You don't need it, but save it just in case you do. :D
     

  3. bradford027

    bradford027 New Member

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    Its an o-ring for under the extractor. Im running a 14.5" and mine works fine without it. I think it adds some uumph for extraction. I would run it without and see how it does, you can always add it later.
     
  4. louieboots

    louieboots New Member

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  5. JonM

    JonM Moderator

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    if you can manage to get it in the bolt it REALLLLLLY chucks the empties FAR