Pressure flats

Discussion in 'ELR, Ballistics & Bullets Board' started by tomswede, Jan 8, 2018.

  1. Ned Ludd

    Ned Ludd Silver $$ Contributor

    May 28, 2012
    Which is exactly why it makes more sense for the manufacturer to simply list the G7 BC values, which are relatively insensitive to velocity. Then the thousands of end users don't each have to do the same thing on their own, or simply live without the best information when they're trying to do load development or compete. Advertising high velocity band G1 BCs is, in part, exactly that...advertising. It allows the manufacturer to list a slightly higher BC value, which may have a positive impact on sales for anyone comparing their product to a competitor's product. It may not be the sole reason, but it's at least a part of it. As long as the provided information is factually correct, there's nothing necessarily wrong with this approach, and in fact, advertising has been carried out this way since its inception. However, providing consumers with the most useful product information, even if it may not allow a manufacturer to distinguish their product as well from that of a competitor, can also generate consumer good will and confidence, which might also lead to increased sales.

    As far as the pressure/velocity flats, they do exist. If you aren't seeing them, the easiest thing to try is test a few different primers. I have no idea whether loading to the center of pressure flats is a commonly used approach in other types of shooting, but there are plenty of F-Class shooters that pay close attention to them. If you load to the center of a charge weight window where pressure/velocity increase minimally relative to other regions of the charge weight/pressure/velocity curve, you are also loading to a region where velocity is likely to be minimally affected by temperature changes. That can make a difference over the long (20+) shot strings we typically fire in F-Class matches.
  2. Cowtownup

    Cowtownup Silver $$ Contributor

    Feb 19, 2015
    Tom, did you shoot this ladder horizontally to look for POI shift while you got velocity data?


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