front iron sight 6.25 or 7.50??

Discussion in 'AR-15 Discussion' started by jrl78, Apr 9, 2013.

  1. jrl78

    jrl78 New Member

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    Hey there everyone, looking to put a standard a frame front iron sight on my ar. On bravo company website they have one listed as a 6.25 and another as a7.50. What's the difference???
     
  2. Quentin

    Quentin New Member

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    You need to measure the diameter of your barrel at the gas port then get that size FSB. Usually 0.750" fits gov't and M4 profiles while 0.625" fits pencil barrels. Your numbers are off by a factor of 10.