Mid length gas system vs. carbine length

Discussion in 'AR-15 Discussion' started by sparky17, Feb 20, 2012.

  1. sparky17

    sparky17 New Member

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    I am looking to get my first AR. I have been doing my research for a few weeks and have a question. What are the differences ( other than the length ) of mid length and carbine length gas sytems? Are there advantages to either? I am looking at Rock Rivers. I will mostly be plinking at the range with some coyote / praire dog hunting thrown in.
     
  2. Jpyle

    Jpyle New Member

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    Main purpose of the carbine length gas system was to allow sufficient pressure to remain in the barrel to cycle the bolt on the original military M4 equipped with a 14" or shorter barrel. No real advantage to having it on a civilian AR other than retaining the M4 look. It will generally have a sharper recoil impulse than a mid length or rifle length system, but that can be mitigated with a heavier buffer. A shorter gas system will also shorten the sight radius if you use a standard A2 type FSP. Personally, of the three I prefer the mid-length as it has a softer recoil and offers more foregrip and sighting choices without necessarily having to go to a lo pro gas block.
     

  3. robocop10mm

    robocop10mm Lifetime Supporting Member Lifetime Supporter

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    The "carbine length" gas system was used on the 16" guns way before the M-4 was dreamed up. What ever gas system is used, it must have a gas port drilled to balance gas system length, barrel length and gas port size. The carbine length or mid length can be used on a 16" barrel but the port size will be different.
     
  4. AgentTikki

    AgentTikki New Member

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    Unless you have a lo profile gas block a free float a oversized rail/hanguard over it:

    Middys have 2 inches more rail to hold onto, and 2 inches more sight radius, but trade of off a little eight for it.

    IMHO since most manufacturers over gas their systems, the whole smoother cycling thing is a moot point.
     
  5. Quentin

    Quentin New Member

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    What barrel length are you looking at? What kind of ammo, Wolf or high powered or everything? Which buffer weight will you get? AR or M16 bolt carrier? Does your manufacturer choose the best gas port size for each system? There are advantages to each gas system length but you need to fill in more blanks before choosing which is best for you. If it comes down to a tie I'd go with the longer gas system if it will reliably cycle your rifle.
     
  6. sparky17

    sparky17 New Member

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    Barrel length is 16". Shooting mostly handloads since I also have Remington 700 bull barrel 223. Buffer and bolt carrier (AR?) would be standard for Rock River Arms.
     
  7. fsted2a

    fsted2a Active Member

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    Back in the late '90's, there was someone who was making pigtail shaped gas tubes to increase the length of the tube so the carbine would be the same length tube as a 20 inch barrel. I don't know if it worked, or people didn't want to spend some time and money finding out.
     
  8. Quentin

    Quentin New Member

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    From what I've read it didn't do much, an extra 2" of gas tube had little effect. What makes the difference is where the gas port is on the barrel.
     
  9. purehavoc

    purehavoc New Member

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    I think Brownells still sells those