Case volume

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  • Case volume


    I am looking at starting reloading and have been retaining my spent cartridges to eventually reload (which I have maybe four different brands). I have been reading Nick Harvey's manual and mentioned the varying volumes of different manufacturers cases. From seasoned reloaders, have you found any significant differences in volumes or are they negligible? I will be reloading 204 & 308 .

    Thanks, Rob.

  • #2
    the easiest way to deal with case volumes is to have all your cases full length sized (uniforms outside dimensions) then trimmed to length (uniforms length) then weigh the cases. this will give you an idea of how much brass is in each case and there for how much case volume you have. given that all cases are the same size outside any variations in brass thickness (extra thickness = extra weight) will reduce volume

    if you mix brands of brass you may find large variations in volume, ADI cases are notoriously thick and heavy

    there are methods using water to measure volume, for example weigh a case, fill with water and weigh again, volume is measured in grains of water. too fiddly for most



    • MrCarbine
      MrCarbine commented
      Editing a comment
      Yes there is a variation and it can be quite large. Separate your cases by head stamp and lot number if you can. Keep them separate at all times. The less volume the more chamber pressure you will get. If you develop a load in cases with large volume and then use the same load in a case of lesser volume. You will most definitely know about it (sometimes at a cost of a new rifle). I have some experience at this. Also what 6602steven says.

  • #3
    Unless you are loading hot loads or using a slower powder, case volume shouldn't be a problem. You can batch cases by brand or weight for consistency.


    • #4
      yes it can be important. it just depends how far you want to go in regards of chasing accuracy.
      I've seen at least a 5% variation in different cases.
      not a big problem in large cases, but a 1/2 gr difference in your 204 could be enough to jeopardize some accuracy.
      might be an issue when doing long range shots, but in general,....not a major problem.
      see if you can pick out a top quality brand of brass, and just use that.


      • #5
        Thanks for the replies... I will be full length sizing when I start, but as Steve wrote I think the only way to be sure is to check volumes of each case (time consuming but one of those jobs I'll just have to do). The last thing I want is a damaged rifle.