weigh cases by internal volume or by total weight?

[Joe R]

dmoran
« on: Today at 11:05 AM »

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Monte & Joe-

I respect your own scenario..... and as I wrote in my original reply: "Its not for everybody..."

But if you did want to find potential outliers, and don't mind the extra work, you could go to Plan C and take the more exhausting approach and measure them each cycle until they've settled down (using the outliers as "sighters"). You would also learn a lot about volumes, how they change from cycle to cycle, and brass flow/stretch by taking on the task.

Or just go with the commonly used Plan A, and skip it all together and not worry yourself about volume's !.!.!

To each our own.... Good conversation all the same
Donovan

Donovan,
As you know sometimes I'm stubborn other times I'm just plain stupid, but I eventually do see the light. I understand about the correlation between weight and volume, but my take is simple: why make inferences about volume when you can simply measure it and be 100% sure. I agree with your method of using dry media. Since I already have some IMR8208 around and it is a very fine kernel powder I will probably use it. But that's down the road. Gotta fix my neck tension problem first.

Joe

 

[6BRinNZ]

Monte & Joe-

I respect your own scenario..... and as I wrote in my original reply: "Its not for everybody..."

But if you did want to find potential outliers, and don't mind the extra work, you could go to Plan C and take the more exhausting approach and measure them each cycle until they've settled down (using the outliers as "sighters"). You would also learn a lot about volumes, how they change from cycle to cycle, and brass flow/stretch by taking on the task.

Or just go with the commonly used Plan A, and skip it all together and not worry yourself about volume's !.!.!

To each our own.... Good conversation all the same
Donovan

Donovan - with respect to F-class - where do you see case volume as being an influencer to achieve the desired vertical.

For instance would the priority list look something like this;

primer
powder
seating depth
bullet sorting
case volume
seating depth pressure (neck tension measured by force)

Hopefully the question makes sense. Obviously no right or wrongs just opinions - PM me if wanted.

As a more generalised statement a large number of guys (f-class context) report shooting best with new lapua brass and often spend their time trying to duplicate the characteristics of it - there is even a thread in the oz f-class forums saying this very thing. I've wondered if the firings change the volume and characteristics somewhat and unless you do all of the very detailed prep it can be a bit hit and miss to get the consistency back.

 

[LC Tikka]

Hi All
It is the volume which is important, the actual size of the combustion chamber.
If you are using the volume method, no good using virgin brass as it in not uniform.
Shoot the brass once or twice so it is formed to the chamber, the outside is then uniform, therefore the inside/volume is stable.
Then do the volume sorting, then size how you wish. Sizing will change the volume uniformly one would hope, but at firing the case meets the chamber wall and all is uniform again when it really counts!!
LC

 

[6BRinNZ]

6BRinNZ -

There is a lot of different opinions and expectations amongst us all......
What one might find as acceptable accuracy and calls it great, might not fit the desires of another.
Personally I am on a never ending quest to eliminate all the vertical I can from my loads.
Sort to speak, if I'm getting 10-ES, I'm looking to get it to 5. And at 5-ES I'm trying for 2.......
With that said, my expectations are probably higher, and I will not allow for much volume variance in my match sets.

Again my own inputs here, I have seen volume variance appear from even good brass after forming from large chambers, poor fire-forming methods(inconsistent), and especially in wildcat cartridges that do not blow to consistent lengths when formed. Also from certain brands of brass and calibers. And as I wrote in other reply above, cartridge sizes and capacities make a big difference to how much variance I will allow in my qualifications.

One aspect that I will state is, when I have weeded out culprits and tested them, I see obvious and undesirable amount of fly'er type vertical and increased ES come from them.
Have I seen 10" of vertical from them at 1000 yards: rarity
Have I seen +5" of vertical from them at 1000 yards: yes -- they are the "spoilers"
Have I seen +3" of vertical from them at 1000 yards: often

Regardless, I sleep better before a match when my cases and bullets meet my own specification acceptances !.!.!
Donovan

Thanks - Useful information.