Bolt Carrier Group weirdness...

Discussion in 'Rifle Country' started by halfmoonclip, Jan 24, 2022.

  1. halfmoonclip

    halfmoonclip Member

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    Not long after the Clinton ban sunsetted, built a replica of the M16A1 that the gummint was kind enough to loan me in 1970. Upper, BCG, and furniture was all NOS Colt; NoDakSpud period correct lower; ran great, shot really straight.
    I'd seen the early AR 16" carbine uppers at Brownells, and scored one reasonably at a gun show; no BCG, but I used the Colt one, and it ran fine.
    Like the setup; full sight radius in a carbine, for using irons, but it is a rifle gas system...lack of dwell time was reputed to cause trouble. Reputedly, the Brownells replicas use a bigger gas port to compensate.
    Popped another random BCG in, rather than swapping back and forth...and it ran sporadically.
    Scored another Colt BCG at a show; this, a half circle carrier, likely from an SP1.
    This one runs just fine.
    So, no big deal, but what would make a difference? Same 55 gr milspec ammo in both cases?
    Thots?
    Moon
     
  2. someguy2800

    someguy2800 Member

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    Leaky gas key? Leaky firing pin hole? Different weight?
     
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  3. halfmoonclip

    halfmoonclip Member

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    Getting the lighter, half circle, carrier was a motive in buying it.
    Some years back, when I was active on Arfcom, the full circle carriers were much preferred to older, SP1 ones; Colt made them that way so they wouldn't work with an autosear.
    The rifle length systems in a 16" carbine was reputed to be an issue.
    Moon
     
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  4. 12Bravo20

    12Bravo20 Member

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    And they are still a problem. That is why most of the Dissipator models you see will actually use a carbine gas system hidden under the handguards.
     
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  5. CarJunkieLS1

    CarJunkieLS1 Member

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    Why anyone would think a rifle gas system on a 16" barrel is a good idea is beyond me.

    For a reliable shooting and a little softer shooting the mid length gas system is a far better option.
     
  6. mjsdwash

    mjsdwash Member

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    didnt colt Rockset their key? Thats the only gas difference i know of.
     
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