AR extraction curiosity

Discussion in 'AR-15 Discussion' started by linuxuser3890, Jan 21, 2012.

  1. linuxuser3890

    linuxuser3890 New Member

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    Do ya'll think that when the bolt rotates to unlock and begin extraction, the empty case rotates with the bolt or is there too much friction. I would like to get your theories and supporting evidence because I'm curious. Maybe steel does and brass doesn't or vice versa. I noticed while reloading that all my brass had marks from the extractor but I can't determine if it is from it digging in because the case won't rotate or if it is from when it was held while the case rotated by force from the ejector. Just curious and maybe slightly bored atm.

    Sent from my Inspire 4G using FirearmsTalk
     
  2. j_lum

    j_lum New Member

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    I had an extractor break awhile back, and they were backordered indefinitely, I welded some material back into it and machined it back as close to spec as I could, but there was a very small bit of play in the 'claw' itself. It worked, but it marked all the brass because it was slipping. I think the casing typically starts to twist with the bolt due to the grip of the extractor, which is multiplied by the force of the bolt traveling back.

    I'm not a gunsmith, and really have no clue other than what I observed in my case.
     

  3. Quentin

    Quentin New Member

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    Good question! I've always assumed the brass did rotate with the bolt since the extractor holds it pretty tight. If it did rotate that would help break it loose from the chamber and avoid extractor marks on the rim. I suspect what actually happens varies in different rifles.
     
  4. Paladin201

    Paladin201 New Member

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    I'm with you, I think it's going to vary from gun to gun and ammo to ammo, but I've never even given it a thought. Just out a curiosity, I went and examined a bunch of my own spent brass. If the case rotated in the chamber I would think I'd see at least some very light scratches running, but I don't.
     
  5. 75370

    75370 New Member

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    When the gas pressure hits the chamber inside the bolt carrier group that force should push forward against the bolt initially, because it's lighter,and unlock the the locking lugs , then the bolt carrier group as a whole will move to the rear and cycle the rifle.
    Short story is no, it shouldn't twist the fired round out of the chamber. If you are seeing the scuff marks from the extractor, it's from feeding the round in the chamber.
    This usually happens with reloaded rounds that have been sized to a very tight chamber spec.
     
    Last edited: Jan 21, 2012