Help - 20"bbl velocity

Discussion in 'General Rifle Discussion' started by hillbilly68, Oct 9, 2008.

  1. hillbilly68

    hillbilly68 New Member

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    Gents,
    I dont own a chrony, anyone have any velocity data for factory 175gr match Black Hills HPBT(SMK) .308 from a 20" bbl? I have searched, only data I can find is for 24 or 26" bbls. thanks
     
  2. Ram Rod

    Ram Rod New Member

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    Here's a couple different sources for you. Hope this helps.

    MV 2000-2500 fps, the approximate change in MV per 1" change in barrel length is 10 fps.
    MV 2500-3000 fps, the approximate change in MV per 1" change in barrel length is 20 fps.
    MV 3000-3500 fps, the approximate change in MV per 1" change in barrel length is 30 fps.
    MV 3500-4000 fps, the approximate change in MV per 1" change in barrel length is 40 fps.

    For rifles with muzzle velocities in the 1000-2000 fps range, the change in velocity for each 1" change in barrel length is 5 fps.
    For rifles with muzzle velocities in the 2001-2500 fps range, the change in velocity for each 1" change in barrel length is 10 fps.
    For rifles with muzzle velocities in the 2501-3000 fps range, the change in velocity for each 1" change in barrel length is 20 fps.
    For rifles with muzzle velocities in the 3001-3500 fps range, the change in velocity for each 1" change in barrel length is 30 fps.
    For rifles with muzzle velocities in the 3501-4000 fps range, the change in velocity for each 1" change in barrel length is 40 fps.
     

  3. 7600

    7600 New Member

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    I don't know if this helps, but I get 2559 f.p.s. out of my 18.5 inch barrel with remington 180 gr. loads.