Has/does anyone track brass performance down to the individual case level?
Some benchrest shooters do, or at least have tried to see what results can be achieved. Some even tried shooting each cartridge with the same roatational angle and noted the position of each impact to try to duplicate each shot. Some have reported some success. Top bench shooters pay a lot of attenetion to barrel performance and to consistancy in doing everything the same for each shot. For example, the time a cartridge sits in the rifles chamber or how long it sits in the sun before it's chambered will affect velocity too. So will the residue left in the barrel from previous shots.
There are lots of factors in achieving better accuracy. I think ti's worth applying my efforts where they'll do the most good in overall performance. Not all shooting is the same. What gives accuraracy with 25 yard pistol, 100 and 200 yard behchrest, 1000 yard benchrest, and variable distance long range hunting have some similarities but also a lot of differences. Each of us only has a finite amout of time to apply to our shooting. That can vary a lot from person to person.
Bryan Litz's book "Applied Ballistics for Long Range Shooitng" has a good section on how various error souces combine. It's good reading for any shooter but partiularly for long range hunting.. Unlike target shooters, first shot cold barrel shots are far more important for hunters and far more difficult to achieve than punching small groups after you've gotten on target with a couple of sighter shots. In damp weather with soft soil there are no dust puffs to tell where your misses impact. When the first shot miss all you know is that it wasn't done right often with no clue how to correct it.
My point is that for hunting, buying or building a rifle and ammo which does not requre extaordinay effort is practical to achive the situation where enviromental factors, usually wind, overwhelm the launch angle or velocity dispersion errors. It makes sense to put your effort both in equipment and personal training where it will do the most good. Reading and comprehending Brian's book is a good use of time for a few hours to understand the effects of range estimation, wind estimation, and ammo variablity. Practicing target shooting in field conditions, particularly learning to estimate wind and wind deflection, is more likley to result in hunting success than loading bechrest quality ammo. Practicing stalking is very worthwhile. Taking shots at game beyond one's capabilities is not what long range hunting is about.
I think you should do that testing Reloader222.
And I think you should test to see if it HURTS anything to match cases by volume.
I believe alot of folklore(and laziness) w/regard to capacity testing has poured out of the point blank BR shooters, who would be least affected by moderate volume variances, yet very easily spot obvious offenders by weight and range flyers. Afterall their tiny cases(6ppc) amount to 223AI capacity, and they run extreme pressure loads that work around affects of common capacity variances. This is why they can shoot incredible groups while not even measuring powder weight.
But all that's a different world from hunting cartridges.
I promise it won't hurt any of you a bit to check your capacities.
That's great Reloader222.
Also, be sure to log weight-vs-volume, and qualify the method and condition of volume and weight variances for your test loads.
Before testing, take your gun to it's baseline with prefoulers and warmups that measure as expected across a chronograph.
Ya see, you have to actually isolate, identify and correlate, the variances from each other. Else capacity variances might actually be initial loaded volume differences, rather than actual case capacity variance. While this would probably affect change, it isn't the same change.
Your case preps would need to be taken to standard as well. If for example, you 'cause' weight and/or volume variances by changing trim length, then all results could be compromised.
Not to discourage your testing, this is a good endeavor on your part.
Just reminders, as the results would & should be challenged regardless of implication.
Keep us posted