Triangle Groups

Discussion in 'Reloading' started by trailrider121, Dec 21, 2011.

  1. trailrider121

    trailrider121 Well-Known Member

    Messages:
    394
    Joined:
    May 12, 2010
    How many of look for triangle groups when doing load test? Say you run a ladder or ocw test and you find a good node and has a nice triangle group. Do you guys adjust load with powder to shrink triangle and see if it holds, or do you ignore triangle groups? Or go with the group that produces the best?

    I would like to hear when you guys find a good node and adjust group size. Powder first or seating adjustment? Curious...
     
  2. RockZ

    RockZ Well-Known Member

    Messages:
    899
    Joined:
    Mar 10, 2006
    I adjust powder to reduce the es/sd and get a stable velocity to eliminate vertical dispersion.

    Then I change seating depth to bring the group into one hole.

    Remember some barrels will not shoot certain bullets well. No matter how hard you try.
    So don't wear yourself and your barrel out trying to get a bullet to shoot because you like it.

    Shoot what your barrel likes.

    It will be very obvious as you try different bullets.
     

  3. J E Custom

    J E Custom Well-Known Member

    Messages:
    7,261
    Joined:
    Jul 29, 2004
    A triangle group normally means that the load is not perfectly in tune with the rifle.

    Stringing is not good because it can mean so many things,trigger control,bedding, wrong powder
    or charge, wrong bullet, wrong seating depth, wrong primer, ETC.

    Triangle shaped group can be as simple as parallax, hold consistency or a good load that needs
    fine tuning with different seating depths and is a good sign that you are close to finding a
    very accurate load combination for your rifle.

    I have recently seen this in a rifle that was shooting almost a perfict triangle every time
    but it would be orientated differently every time. I could take the targets and overlay them
    on top of each other and when I rotated them the group would line up and almost perfectly
    match the one below.

    Turns out the size of the group(just over an Inch) was the load and the parallax was the cause
    of the group rotating.

    A scope change and a little more load develoupment cured the probablem.

    So the answer to your question is yes,a triangle shaped group is normally a good sign.

    J E CUSTOM