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amamnn · December 28, 2006, 02:24 PM

If you want to shoot the kind of groups we see in competition, and you and your rifle are 100% then you're going to want to stop worrying so much about the weight of your cases and start culling them by volume. Weight is not an exact predictor of the capacity of your cases. Cases that weigh the same sometimes do not have the same capacity, and in extreme cases heavier brass may actually have more volume than lighter cases. You must be able to make every dimension of your cases uniform, Also, you are going to want to learn how to measure the density of your powder and figure your load variation based on the volume density relation. If you have a scale that weighs in grams it is a big help in making the calculations since 1 cc = 1 gram = 1mL of water (the density standard)

You will also want to ensure concentricity, bullet length from base to ogive and from base to tip (meplat) and a host of other variables that need to be controlled. Here is a good place or two to start---

http://www.6mmbr.com/index.html
http://www.benchrest.com/
http://nbrsa.benchrest.com/
http://www.sinclairintl.com/

December 28, 2006, 02:24 PM	#2
amamnn Senior Member Join Date: May 13, 2006 Location: WA, the left armpit of the USA Posts: 1,323	If you want to shoot the kind of groups we see in competition, and you and your rifle are 100% then you're going to want to stop worrying so much about the weight of your cases and start culling them by volume. Weight is not an exact predictor of the capacity of your cases. Cases that weigh the same sometimes do not have the same capacity, and in extreme cases heavier brass may actually have more volume than lighter cases. You must be able to make every dimension of your cases uniform, Also, you are going to want to learn how to measure the density of your powder and figure your load variation based on the volume density relation. If you have a scale that weighs in grams it is a big help in making the calculations since 1 cc = 1 gram = 1mL of water (the density standard) You will also want to ensure concentricity, bullet length from base to ogive and from base to tip (meplat) and a host of other variables that need to be controlled. Here is a good place or two to start--- http://www.6mmbr.com/index.html http://www.benchrest.com/ http://nbrsa.benchrest.com/ http://www.sinclairintl.com/