checking volume of brass

[FURMAN]

I've talked to a whole lot of actual experts at several of those companies over the years and not one of them has said that.

Nosler in fact charges extra for their fully prepped and weight sorted brass.

Variations in wall, shoulder, and neck thickness mean differences in weight and they also will correspond to differences in volume.

Sort, don't sort, sort by weight, sort by liquid volume, whatever suits you but let's don't have any more passing off of bad information as gospel. It doesn't help anyone.

For the average hunter and reloader it probably won't make enough difference to matter but then they are just trying to hit a 10" target at a maximum of 200yds.

For long range precision shooting it's one more variable that is within our control so it's worth doing.

I have had multiple manufacturers tell me weight sorting is not accurate. I repeat several. I am not going to say who on this open forum. It is what made me check in the first place. With most of the available brass manufacturers I have checked each individual case using both methods and, as stated several times, I found the statement to be false. The es and sd of weights was so close(within a few tenths of a grain) I will never measure volume again unless just checking for comparison between different cartridges.

 

[WildRose]

yes either 30 percent or 5%. Pure alcohol was still out of bounds for CCI. I got the answer that I was looking for. I will purchase plugs and measure that way. Peterson cases is getting back to me on accuracy and case volume vs weight.

why not simply use the spent primers you already have after firing?

If you wet tumble your brass it will be as clean inside as it is outside and you can certainly leave the spent primers in for doing so.

When you're finished simply deprime and you can always repeat the cleaning process.

 

[WildRose]

I have had multiple manufacturers tell me weight sorting is not accurate. I repeat several. I am not going to say who on this open forum. It is what made me check in the first place. With most of the available brass manufacturers I have checked each individual case using both methods and, as stated several times, I found the statement to be false. The es and sd of weights was so close(within a few tenths of a grain) I will never measure volume again unless just checking for comparison between different cartridges.

I've been talking to the guys at Nosler and Hornady along with Norma for decades and none of them ever told me that. It may depend on who you're talking to or maybe they are just restricted from what they can say and I happened to catch them or they felt like they've dealt with me long enough to be a little more free in our discussions. I have no idea.

Personally I was on again/off again with respect to weight sorting for a very long time and it was only after getting sound advice here from people I respect that I became convinced it was worth doing for anything I was intending to reach beyond 600yds with and definitely with respect to those I intend to be shooting at 80-1000.

We're dealing with essentiall a sealed chamber under extreme temperatures and pressure and any change in the internal volume has to have an effect. How large that effect proves to be probably depends greatly on the overall volume of the case, weight of the bullet and burn rate of the powder chosen.

From what I've seen, the smaller the case and faster the propellent the more difference it seems to make.

 

[J E Custom]

I am by no means an expert, but the one thing I do believe is that the more consistent everything is , including case volume, The more inherent accuracy and pressure there is.

Good accurate volumes does not automatically guarantee good groups, just like good SDs does not guarantee good groups. I believe that you need to work on one issue at a time. I have a very good load that has SDs below 4, 5 shot groups below .070 thousandths, all cases are weight sorted to within 1/2 grain, and when testing consistency the best groups were with loaded ammo with NO concentricity issues (.000 run out ) with the same ammo loaded with .001 thousandths, accuracy was not as consistent. The more run out the ammo had the worse the accuracy got.

Once I reach .004 the accuracy fell of to more than twice the original group size. the same was true with cases that weighed more than 2 or 3 grains more or less. some bench rest shooters use only one case for the match for this reason (Consistency)

Everything you can do to make everything more consistent will make an improvement in the consistency of your ammo (Accuracy) what ever method you use to load the most consistent ammo is a plus in my opinion.

If everything is exactly the same, and is as near perfect as possible, the only variable is the shooter.

J E CUSTOM

 

[Steve Sheasly]

I am by no means an expert, but the one thing I do believe is that the more consistent everything is , including case volume, The more inherent accuracy and pressure there is.

Good accurate volumes does not automatically guarantee good groups, just like good SDs does not guarantee good groups. I believe that you need to work on one issue at a time. I have a very good load that has SDs below 4, 5 shot groups below .070 thousandths, all cases are weight sorted to within 1/2 grain, and when testing consistency the best groups were with loaded ammo with NO concentricity issues (.000 run out ) with the same ammo loaded with .001 thousandths, accuracy was not as consistent. The more run out the ammo had the worse the accuracy got.

Once I reach .004 the accuracy fell of to more than twice the original group size. the same was true with cases that weighed more than 2 or 3 grains more or less. some bench rest shooters use only one case for the match for this reason (Consistency)

Everything you can do to make everything more consistent will make an improvement in the consistency of your ammo (Accuracy) what ever method you use to load the most consistent ammo is a plus in my opinion.

If everything is exactly the same, and is as near perfect as possible, the only variable is the shooter.

J E CUSTOM[/QUOte
excellent post. For every 10 rounds you load for the same rile the rifle may only like one or two --- and the shooter is always the most inconsistent variable. I do what I can but i am human. Timney triggers have helped me a lot set pretty light.

 

[Steve Sheasly]

this is what I was told. Having worked with foundry's and with extrusion processes for decades I know that tolerances are very good but not perfect. The head of the case holds the most weight of the case and is also where the most variability is.
s The inconsistency of this one variable is enough for me to justify volume sorting vs weighing (by the way the people I asked at the companies mostly weight sorted they think it is close enough -- now this is one person out of many employees there might be those that volume sort too). Is it possible that you did not ask the right question? Maybe you did? If you still have connections with these manufacturers ask them the exact question

Not every one will just offer information especially if they do not know. Make sure you ask the person who's responsibility is quality control. Facts are facts assumptions are assumptions and not good data. I would certainly like to hear what you are told.
Your last sentence sums it up nicely.

 

[J E Custom]

this is what I was told. Having worked with foundry's and with extrusion processes for decades I know that tolerances are very good but not perfect. The head of the case holds the most weight of the case and is also where the most variability is.
s The inconsistency of this one variable is enough for me to justify volume sorting vs weighing (by the way the people I asked at the companies mostly weight sorted they think it is close enough -- now this is one person out of many employees there might be those that volume sort too). Is it possible that you did not ask the right question? Maybe you did? If you still have connections with these manufacturers ask them the exact question

Not every one will just offer information especially if they do not know. Make sure you ask the person who's responsibility is quality control. Facts are facts assumptions are assumptions and not good data. I would certainly like to hear what you are told.
Your last sentence sums it up nicely.

You are absolutely correct about the cartridge base possibly being thicker/different, but if it is it will change the volume and the weight. The only real variable that we cant measure by weighting or a volume test is the extractor groove. Its depth or width
can have effect on weight but not volume. the reason that volume testing can still be the best if done correctly. but the difference in weight is almost immeasurable if at all
because it is normally machined and very consistent.

Measuring the extractor groove is a very difficult way to look for any difference and calculate the weight difference so I ruled it out as a factor. Like you, I have ran many test and found one thing that improved performance. "Consistency" in all things related to loading no matter how you achieve it, It always improves performance.

J E CUSTOM

 

[Steve Sheasly]

You are absolutely correct about the cartridge base possibly being thicker/different, but if it is it will change the volume and the weight. The only real variable that we cant measure by weighting or a volume test is the extractor groove. Its depth or width
can have effect on weight but not volume. the reason that volume testing can still be the best if done correctly. but the difference in weight is almost immeasurable if at all
because it is normally machined and very consistent.

Measuring the extractor groove is a very difficult way to look for any difference and calculate the weight difference so I ruled it out as a factor. Like you, I have ran many test and found one thing that improved performance. "Consistency" in all things related to loading no matter how you achieve it always improved performance.

J E CUSTOM

you and I think alike. I asked the question how could the heads in the same lot weigh differently. I was told that the sheet the cup is made out of has different densities therefore different weights in the same sheet.
I was in the paper industry for 45 years. Paper for sure has different densities or caliper across a sheet I would think brass would too. I had never heard this before either.

 

[cohunt]

Brass alloys do differ from lot to lot and definately between manufactures.

The first thing I was taught in precision reloading is "consistancy is accuracy" ....the 2nd thing I was taught was "perfect practice makes perfect"

 

[Pdvdh]

Brass is so much denser than water, I think weighing the brass cases is better able to ID differences in brass volume, compared to differences in the weight of water volume. If a guy used liquid mercury, volumetric weighing of the case volume would be better. But the reloader would die from mercury toxicity.
I don't doubt that case brass varies slightly from manufacturer to manufacturer. I do doubt that the magnitude in difference in density is significant. And if a guy is weighing and comparing cases by individual brands, the brass will be constructed with brass of equal density.
Weighing individual cases is so simple and straightforward, it's something I'm willing to do. Messing with liquids and then weighing the liquid content of every casing..., no. Not me. At some point the fun is taken out of the hobby. Each to his own interests and idea of fun.

 

[Steve Sheasly]

Brass is so much denser than water, I think weighing the brass cases is better able to ID differences in brass volume, compared to differences in the weight of water volume. If a guy used liquid mercury, volumetric weighing of the case volume would be better. But the reloader would die from mercury toxicity.
I don't doubt that case brass varies slightly from manufacturer to manufacturer. I do doubt that the magnitude in difference in density is significant. And if a guy is weighing and comparing cases by individual brands, the brass will be constructed with brass of equal density.

The point is that even with the same lot -- same brand --- cutting the exact same size and shape cup out other the same sheet of brass can and sometimes will result in different weights. Lets take this example.
Lets take 2 cases identical - lets drop one at a time into a glass of water and measure the displaced water. Lets say that the displaced water is exactly the same in grains of weight. Ok -- now lets weigh the brass cartridges --- they do not weight the same because of different densities in the parent brass. I have found this to be the case by my own measurements. Up to 5 grains off. Will this make a difference to every one? Nope not by a long shot (pun intended) but to me it does. So volume is the only way for ME to sort brass and the only way at all to get the same void volume with the powder in the case ready to seat the bullet. Wich by the way is super critical to void volume. If you do not seat the bullet with the same depth of the projectile then measuring volume is worthless. In my opinion we with brass not because it makes our guns lighter (joke) but because we want the same exact void volume so the powder during ignition burns the exact or as close to the exact same as possible.

 

[FURMAN]

The point is that even with the same lot -- same brand --- cutting the exact same size and shape cup out other the same sheet of brass can and sometimes will result in different weights. Lets take this example.
Lets take 2 cases identical - lets drop one at a time into a glass of water and measure the displaced water. Lets say that the displaced water is exactly the same in grains of weight. Ok -- now lets weigh the brass cartridges --- they do not weight the same because of different densities in the parent brass. I have found this to be the case by my own measurements. Up to 5 grains off. Will this make a difference to every one? Nope not by a long shot (pun intended) but to me it does. So volume is the only way for ME to sort brass and the only way at all to get the same void volume with the powder in the case ready to seat the bullet. Wich by the way is super critical to void volume. If you do not seat the bullet with the same depth of the projectile then measuring volume is worthless. In my opinion we with brass not because it makes our guns lighter (joke) but because we want the same exact void volume so the powder during ignition burns the exact or as close to the exact same as possible.

How many cases have you measured this way? I have measured hundreds comparing the internal volume, the external is identical for all intents and purposes, to the weight. In EVERY SINGLE instance I have found that the extreme spread and standard of deviation between the volume and weight are near identical percentage wise. What that says is that the metric used to determine brass consistency is irrelevant. I am not telling you there is no difference in weight(volume) in the same lot of brass with some manufacturers. There absolutely is. This is one reason why we buy the better brands of brass such as Lapua or Nosler. It sounds like the OP has made up his mind and insists on checking volume and it makes no difference to me. To new reloaders wanting the most consistent brass checking volume is a waste of time. Weight sort and be done with it.

 

[Pdvdh]

Don't mix different brands of brass? Use the same lot # of brass casings.
Then weigh brass cases.
Do you think the density of brass and the machining tolerences of the extractor grooves varies substantially within the same brand and lot number of cartridge cases?

I'm not suggesting mixing different manufacturers' casings. And don't use Acme brand from the Road Runner wily coyote cartoon.

 

[Pdvdh]

Using 100% grain alcohol, Everclear, has it's useful advantages. But only if consumed. I'm not wasting it for volumetric cartridge case measurements.