What is exceptable brass weight deviation?

Discussion in 'Reloading' started by padreweis, Dec 13, 2012.

  1. padreweis

    padreweis Well-Known Member

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    I am playing around with weighing some 300wm brass. Can anyone tell me what accecptable differences should be? For instance out of 100 cases the weight ranges from 234.5 grains to 240 grains. So basicly that gives me a 3 percent deviation.

    80% of them fell between 237 and 239 grains which is less than 1 percent. Should I just use those as my working pool?

    Any clarity someone can provide would be awesome.
     
  2. Kevin Thomas

    Kevin Thomas Well-Known Member

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    Sinclair recommends a variance of 1.5% as being an acceptable range, and that's one that should leave you with a workable amount of brass. This is the standard that I've held my match brass to for some time now, and I have no complaints with this tolerance.

    Weigh them all, separate them by .1 grain increments and see how they fall on a bell curve. Discard those that fall outside the 1.5% range and keep those in the middle as your working brass. Should be good to go from there.
     

  3. padreweis

    padreweis Well-Known Member

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    Thanks Kevin! That answered it perfectly.
     
  4. Kevin Thomas

    Kevin Thomas Well-Known Member

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    Glad to help!
     
  5. blackdog

    blackdog Well-Known Member

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    Kevin - now will you please start making some 300 win mag brass again that meets those standards?!?!? :D