Weighing new brass

[lancetkenyon]

really? So If I take a steel cylinder and weld weight on to the outside of it the volume changes -- as an example.

That changes the outside dimensions. Now take that same weight, and add it to the actual wall thickness, or drop it inside, then yes, it changes the volume capacity of the cylinder.

 

[Hand Skills]

But then your steel cylinder won't fit in the chamber....

Assuming consistent exterior dimensions, I don't follow...

 

[Steve Sheasly]

Maybe that was a bad example. But weight does not always correlate with volume unless you have concentric, uniform homogenous case walls. But remember the ejection grooves are machined and the head stamp is,slammed on while on a mandrel in the cylinder shape before final tapering. The most variation I have personally measured is 2 grains of volume for identical weights .It,does indeed happen

 

[Barrelnut]

Maybe that was a bad example. But weight does not always correlate with volume unless you have concentric, uniform homogenous case walls. But remember the ejection grooves are machined and the head stamp is,slammed on while on a mandrel in the cylinder shape before final tapering. The most variation I have personally measured is 2 grains of volume for identical weights .It,does indeed happen

This is all well and true. Differences in external dimensions of unfired cases, ejection groove dimensions, and case wall thicknesses, even differing case head thickness will affect the weight. But once you have everything stretched out by firing the case, the weight of the case will pretty much reflect the volume of the case. It is NOT 100%, but in about 90% of the cases, IMO, it will be true. So, I just cannot justify the difference in time it takes to weight sort cases vs volume sorting them. In most instances, weight sorting, will expose those cases that have volume capacities big enough to affect long range accuracy. Not ALL of them, just most of them.

 

[Steve Sheasly]

This is all well and true. Differences in external dimensions of unfired cases, ejection groove dimensions, and case wall thicknesses, even differing case head thickness will affect the weight. But once you have everything stretched out by firing the case, the weight of the case will pretty much reflect the volume of the case. It is NOT 100%, but in about 90 of the cases, IMO, it will be true. So, I just cannot justify the difference in time it takes to weight sort cases vs volume sorting them. In most instances, weight sorting, will expose those cases that have volume capacities big enough to affect long range accuracy. Not ALL of them, just most of them.

Remember in once,fired,cases the internal brass was just subjected to a hot and rapid expansion of corrosive gasses which can cause deposits which affect volume not proportional to weight because the deposits are not brass . I take the extra step because I want,to know exactly where my bullet is supposed to go. Until I flinch! Good,luck with your reloading.

 

[Barrelnut]

Aye aye, sir!

 

[J E Custom]

There are many that feel that weighting cases is a wast of time, there are also just as many that feel like it is not a wast of time. Anything that is not done properly can be a wast of time, so the solution is to do it properly and get the best results.

If you weigh cases to get volume you must uniform the outside of the case first ether by firing or sizing. you must also trim all cases to the same length after sizing/firing. you must also clean the cases and inside and out and decap the primer so that all you are weighing is the amount of brass in the case.

The object is to render the outside of the cases dimensional'y identical. if this is done, the interior will be very close in volume even though there are small differences in wall thicknesses in different areas , the total volume will be close.

There is no perfect way to get exact volume because any method is not exact, all you want to do is get the case volume as consistent case to case as possible.

Measuring case volume with a medium that contains a wetting agent and using a beret is probably the most accurate but it is also the most difficult and time consuming. but cases measured this way must also be properly prepared as mentioned earlier, before attempting this method, and the results will be very close to weighing.

New cases should be sized and trimmed to length before volume testing no mater which method you use, and fired cases should be cleaned, sized, trimmed and deprimed in order to get a real comparison.

A good example of case volume making a difference is when using commercial brass or military brass. if you prepare both type cases
as mentioned the Military brass will weigh more and have less volume.
The pressure will also be higher with the Military brass because the volume will be less. accuracy can be just as good with ether type case or better if you adjust the powder charge to the same velocity and pressure, but if you try using the two different types of brass with the same load, different results will show up between the two.

A chronograph is the best way to show the differences that case volume makes because most shooters can't see/tell the differences until they try shooting at long/great distances.

So the object of weight testing or volume testing is consistency. Weight sorting done right will yield good results with less effort and mess, so it is the method I prefer because, nothing is a wast of time if it improves consistency. After all this prep and sorting you must still load good concentric ammo or everything can be considered a wast of time.

Just my opinion

J E CUSTOM

 

[Steve Sheasly]

exactly right. I did after many hours find a procedure that produces consistent and repeatable results. I took one case and prepped it as you suggested above including neck turning, flash hole cleaning, deburring, chamfering, once fired cleaned and polished.
Then I put a new primer in this one case. I filled the case with various powders, including salt and not one time did any of these materials repeat measurement. I took a flat used planer blade to pack and scrape the excess off. I also used a calibration weight and set it on the over filled case. None of these created the same measurement. I was off .1 to 1 grain.
So i took the case used a compressor to clean the case out and filled it with alcohol. Hard to find 200 proof/100% alcohol but it is out there.
Here is what I did to get the measurement to repeat -- exactly over 10 times. It works on other cases as well.
I filled with an eye dropper to the rim then I kept filling as the meniscus rose out of the case (concave with water as water likes itself more than teh case walls. Alcohol is exact opposite so a convex meniscus is the resultant) I kept adding one drop until it just spilled over the lip. A tissue soaked up the very small amount and my loading room is kept at a constant temperature as well so the alcohol evaporates quickly. So I have the procedure by empirical testing and data that is consistent and repeatable forrgot to mention. I would tare my scale with each case. Then put the case back on the scale an most of the time i was .5 grain high so I would blow the case out and it would tare. Then I built a spread sheet to log the results. An average deviation or standard deviation was not applicable although these results are on my spread sheet. I wrote my own formula using Max -Min function to get spread and set the alarm at .5 grain volume difference. Then I group the brass and use the one with the most cartridges and wait to populate the other groups.
I do have 100 cases of Lapua .338LM coming tomorrow. I will do the same on this brass with out firing just to see how close they are.

I know this is a lot of work. But i only load 100 rounds or so for hunting and use the rest on my own range. I can go out thousands of yards in my back yard. We live on a wheat ranch.

I hate using alcohol on a primer then loading the case to fire. I have an email into CCI to see if alcohol will ruin or negatively affect the ignition of the primer.

 

[J E Custom]

exactly right. I did after many hours find a procedure that produces consistent and repeatable results. I took one case and prepped it as you suggested above including neck turning, flash hole cleaning, deburring, chamfering, once fired cleaned and polished.
Then I put a new primer in this one case. I filled the case with various powders, including salt and not one time did any of these materials repeat measurement. I took a flat used planer blade to pack and scrape the excess off. I also used a calibration weight and set it on the over filled case. None of these created the same measurement. I was off .1 to 1 grain.
So i took the case used a compressor to clean the case out and filled it with alcohol. Hard to find 200 proof/100% alcohol but it is out there.
Here is what I did to get the measurement to repeat -- exactly over 10 times. It works on other cases as well.
I filled with an eye dropper to the rim then I kept filling as the meniscus rose out of the case (concave with water as water likes itself more than teh case walls. Alcohol is exact opposite so a convex meniscus is the resultant) I kept adding one drop until it just spilled over the lip. A tissue soaked up the very small amount and my loading room is kept at a constant temperature as well so the alcohol evaporates quickly. So I have the procedure by empirical testing and data that is consistent and repeatable forrgot to mention. I would tare my scale with each case. Then put the case back on the scale an most of the time i was .5 grain high so I would blow the case out and it would tare. Then I built a spread sheet to log the results. An average deviation or standard deviation was not applicable although these results are on my spread sheet. I wrote my own formula using Max -Min function to get spread and set the alarm at .5 grain volume difference. Then I group the brass and use the one with the most cartridges and wait to populate the other groups.
I do have 100 cases of Lapua .338LM coming tomorrow. I will do the same on this brass with out firing just to see how close they are.

I know this is a lot of work. But i only load 100 rounds or so for hunting and use the rest on my own range. I can go out thousands of yards in my back yard. We live on a wheat ranch.

I hate using alcohol on a primer then loading the case to fire. I have an email into CCI to see if alcohol will ruin or negatively affect the ignition of the primer.

A man after my own heart. Test are useless unless they are done carefully and documented like you did.

I had almost the same experiences with all media except alcohol and distilled water with a wetting agent. It was the most accurate but it sacrificed the primers. (I did not use spent primers because they were inconsistent).

Primers were very cheep at the time and it was worth the loss. and after comparing the volume differences and consistency between the two methods, weighing was chosen because of ease of use, time, less mess and overall accuracy.

I still feel that a good volume test is the most accurate, but weighing gets me the same results as long as my case prep is done properly and is still better than doing nothing to match volumes.

Just my opinion

J E CUSTOM

 

[Steve Sheasly]

A man after my own heart. Test are useless unless they are done carefully and documented like you did.

I had almost the same experiences with all media except alcohol and distilled water with a wetting agent. It was the most accurate but it sacrificed the primers. (I did not use spent primers because they were inconsistent).

Primers were very cheep at the time and it was worth the loss. and after comparing the volume differences and consistency between the two methods, weighing was chosen because of ease of use, time, less mess and overall accuracy.

I still feel that a good volume test is the most accurate, but weighing gets me the same results as long as my case prep is done properly and is still better than doing nothing to match volumes.

Just my opinion

J E CUSTOM

your opinion is correct. That is why I only did one case -- when I talk with CCI tomorrow I will tell you what they have to say. Your spent primer comment is spot on! Something others either do not see or they choose to ignore. I am hoping there is no damage by 100% alcohol. Although common sense tells me that CCI would never condone this. I may soak the primers in solution then load them and chrono them against a known load. Just of giggles. and data. Knowledge in the game of accuracy is essential.

 

[WildRose]

really? So If I take a steel cylinder and weld weight on to the outside of it the volume changes -- as an example.

Seriously?

Your steel cylinder isn't being resized to a specific set of specs identical to that of other five hundred it's being compared to.

Every dimension of every piece of brass is consistent to within a few thousandths of an inch.

You cannot change the amount of brass present without affecting the volume it will hold.

 

[Pdvdh]

I like to weigh my casings for multiple reasons. Only the experienced could know, and I don't have it in me at this moment, to mentor the inexperienced.
Count me with the case weighers that have actually been there and done it, versus the naysayers that form opinions from Google searches.

Bigedp51... Your out there listening? Did your Google searches find this Post? The king of Google Search experts...

 

[Steve Sheasly]

That is good. I consider myself a novice. I have only been in shooting sports 55 years. Started reloading in the early 1970s. I never rule out learning new things.

 

[J E Custom]

your opinion is correct. That is why I only did one case -- when I talk with CCI tomorrow I will tell you what they have to say. Your spent primer comment is spot on! Something others either do not see or they choose to ignore. I am hoping there is no damage by 100% alcohol. Although common sense tells me that CCI would never condone this. I may soak the primers in solution then load them and chrono them against a known load. Just of giggles. and data. Knowledge in the game of accuracy is essential.

I am sure that CCI will tell you not to use primers after they have been exposed to ANY foreign material. When I first started loading (About the same time as you) I had an experienced re loader tell me not to touch the primer face with my hands because the oils in my hands would/could contaminate the priming material and cause inconsistent primer burn. effecting the consistency.

Cant prove it does but why take a chance. My priming procedure does not require that I touch a single primer with my hands until it is installed in the case and protected from contamination.

I Am interested in what they say. let us know please.

J E CUSTOM