Semi-Auto / AR-15 grouping question

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by rgonz8, Nov 27, 2008.

  1. rgonz8

    rgonz8 New Member

    Messages:
    3
    Joined:
    Apr 12, 2006
    I was shooting some different loads today in my AR-15 and got some interesting results. With the same load I was seeing two distinct groups form. I believe that this is due to variations in chamber-time, or the time the round sits in the chamber warming up before firing. Is this a common thing to happen with semi-auto fire?

    Elevation was pretty much the same but the two groups are about 1.5" apart. Taken by themselves, the 3 shot group is around .5" and the two shots grouped to the right are .375".

    These 5 rounds were all loaded the same:

    24.5gr Varget
    75 grain Hornady A-Max
    2.260" Cartridge OAL

    Thanks in advance
    Rob
     
  2. ICANHITHIMMAN

    ICANHITHIMMAN Well-Known Member

    Messages:
    4,380
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    Jan 31, 2008
    need a lot more info?

    ie. twist rate,range,manufacture,rest used as many details as possable.
     

  3. gbp

    gbp Well-Known Member

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    Aug 22, 2006
    Are you using a free float assembly?