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ar pistol barrel length

Discussion in 'Handgun Discussion' started by Dizle, Sep 3, 2011.

  1. Dizle

    Dizle albany, oregon Member

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    Im getting ready to start my ar pistol build. And I need some knowledge. There are a few different barrel length options. What are the benefits of 7.5 inch compared to 10 inch. Are shorter barrels as accurate? Do shorter barrels create more recoil?

    Which barrel is best for 100 yard acuracy? Wont be shooting farther than that with it. I eventually will be sbr'ing this gun. So any info would be appreciated

    Thanks
     
  2. Chipperxd

    Chipperxd Buffalo Active Member

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    They say that the 10.5 is more reliable as it uses the stock m4 gas tube system. I have a RRA pistol in 10.5 and it is accurate up to 100 yars that I have shot. I have not tried to shoot it any further either as the local range is only 100 yards. but I really doubt that there is very much difference in accuracy between the two. Haven't shot a 7.5 so take it with a grain of salt. ;)
     
  3. slowstang11

    slowstang11 Beaverton Member

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    The 5.56 performs best out of a 20in+ barrel if that is any indication as to what a a 7.5in barrel will do.
     
  4. Wallygator

    Wallygator Albany, OR Active Member

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    You probably wont see any difference in accuracy. The 7.5" will be easier to shoot like a pistol, but if you are SBRing it, then it doesn't really matter. It kind of depends on how you want the SBR to look and feel when it is completed. In both cases I would recommend a 1/7 twist rate, It will stabilize the heavier bullets, which will be more lethal at the lower velocity. If its just a plinker, than any barrel twist rate should work.

    wg
     
  5. CleverName

    CleverName Southern Oregon Active Member

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    Since you are SBRing it I would go with the 10.5" barrel. The 10.5" barrel is considered a minimum to preserve lethality within 100 yards. Plus the shorter barrels can have reliability issues.
     
  6. iamme

    iamme Lane County Well-Known Member

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    10.5"- more reliable, when you get a suppressor will be covered on that by most manufacturers- 7.5" not soo much.

    Now if you have other lengths covered, 7.5" would be a fun toy to have around!!
     
  7. Dizle

    Dizle albany, oregon Member

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    I don't plan on suppressing it. But thank u for the info
     
  8. cyclesarge

    cyclesarge Eugene OR, DUH! We're ALL in the NORTHWEST Well-Known Member

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    As I always understood it, you really start loosing velocity (and therefor lethality) as you go below 16", this said 10.5 is a compromise, 7.5" would be even more so.

    Even if you're not planning on a suppressor, there is a reason suppressor manufacturers don't warrantee their product on a 7.5" barrel, because so much of the pressure is just coming out the barrel instead of being used to propel the bullet as it does from a longer barrel.
     
  9. chariot13

    chariot13 Near Eugene/Springfield Well-Known Member

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    Shooting a Noveske CQB AR15 at 500 yards - YouTube

    4 out of 5 shots at 500 Meters with a LWRC 10.5-inch SBR - YouTube

    those both are with 10.5" barrels shooting out to 500 meters. I had seen a earlier video a few years ago of a 7.5" barrel out to 500 meters. All of course are Sbr's but with a stable platform & nice trigger along with some skill or luck you could do it with the pistol no less. I have a carbon 15 pistol & i can hit out to 100 yards open sight fairly easily on a bench. Havent tried longer & really don't have any need to.
     
  10. Untamo

    Untamo Tigard (SW Portland) Member

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    I have a 7.5" black hole barrel 1x8 poly with an Adams arms piston kit and it's a champ, fun, and short, super short. Lots of fun and reliable. Try to shoot em both before you buy.
     
  11. slowstang11

    slowstang11 Beaverton Member

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    Have any of you done a SBR AR-15 using 5.45x39 ammo? With 5.56x39 you retain the tumbling leathality at all velocities.