question about case dimensions

Discussion in 'Reloading' started by N10sivern, Jan 21, 2013.

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  1. N10sivern

    N10sivern Well-Known Member

    Aug 8, 2012
    i am working on a project. what i need to know is if the distance from the bottom of the outside case head to the bottom of the inside of the case would be consistent from case to case. i know that the primer pockets can stretch over time, but since this is the thickest area of the case, i don't figure that there is much if any stretching in this area on fired brass. below is a picture of a 223 brass for example. i need to know if i picked up a handful of mixed brass, would there be differences in the distance between the red arrows from case to case, and if so how much would you guess?

  2. g0rd0

    g0rd0 Well-Known Member

    Mar 9, 2012
    there is really only 2 ways to measure that. 1, saw the brass in half length ways and measure (you will note that doing this will ruin your brass). 2, separate your brass by manufacturer (I stick with only fed,my choice) sise and trim to length clean and seat bullets on the EMPTY and unprimed cases then wiegh them empty and full of water (hypo needle through flash hole) subtract the differance and that will give you case capacity. If the cc is consistant +/- 0.5grains your brass is pretty much identical inside
  3. Mikecr

    Mikecr Well-Known Member

    Aug 10, 2003
    No need to seat any bullets in cases to measure H20, nor to bother with the measure until brass is stabilized in dimension(fully fireformed).

    I'd drop a pin in each case & measure with calipers from exposed pin end to case head.
  4. boomtube

    boomtube Well-Known Member

    Oct 8, 2007
    There's no way we can know, SAAMI only specs the outsides of the loaded round. The makers do everything else as they wish and adjust their powder charges as necessary. Fact is, what Winchester's case forming presses did yesterday isn't necessarily what they will do next month.