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best length SBR barrel for 5.56?

Discussion in 'GATE NFA/Class III' started by IQof1, Sep 27, 2012.

  1. IQof1


    Sep 4, 2009
    thinking of building an SBR upper in 5.56 and was very curious as to the best barrel length for this project and why it is so.

    i have read that the 7" barrels will knock your fillings loose so i was kind of leaning towards the 10" barrel.

    thnx in advance!
  2. Zak Smith

    Zak Smith 3Gunner Millennium Member

    Aug 25, 1999
    Fort Collins, CO, USA
    I would recommend 10.5" or longer. Mine is 12"

  3. My 556 barrel is 11.5 inches.
  4. GiggleSmith


    Sep 16, 2004
    East Coast
    I have two Uppers:
    11½ and 20 inches.

    I've contemplated on buying a 4 Inch Upper at a Fun Show I once saw, and 24 AND 26 inch Uppers I've found in catalogs. But so far I've been perfectly happy with both so I never bothered to buy another Upper.

    The shorty's are perfect for SBR matches, the longer ones for CMP/DCM shoots.
    Last edited: Oct 6, 2015
  5. Hef

    Hef Stop Obammunism

    Sep 12, 2004
    Hilton Head, SC
    I have a 10.5" upper on mine. From what I have read, 11.5" is the shortest barrel to get to maintain sufficient muzzle velocity for stability in flight and energy on target, though I haven't tested that myself.
  6. jmack37


    Nov 4, 2004
    SE Michigan
    The mission should always drive the gear.

    I know 10.5" AR uppers can run reliably, but I've seen plenty of problems at that length that don't crop up with 11.5" uppers. 11.5" is my sweet spot for a compact gun that is reliable and maintains adequate ballistics.
    Hef likes this.
  7. tmc4065


    Oct 5, 2015
    From a silencer standpoint, few if any manufacturers warranty a can for less than 10.5" in 5.56. I personally wouldn't go less than that unless you want a hand cannon to piss other people off with at the range :50cal:
  8. SmileForFlash


    Dec 26, 2015
    I own a couple and have always read anything under 11.5 reduces reliability when shooting without a suppressor. I would keep this in mind when purchasing your uppers.