Easy way to measure case capacity ?

[carl1575]

I just went on line to see how to do it, after 17 different ways my eyes were starting to cross and my mind was going numb, I went to my Ken Waters books, he has lots of examples case weight, water capacity, I couldn't find how he did it. Do one of you guys[Pet Way] of doing it, that a OLD car salesman can understand, Carl in Yakima

 

[DeltaBravo]

Well, I just fill up a case with the powder I'm using, make it level with the top of the neck, and weigh the powder. I do this several times to get an average. I use this as my basis for determining case % fill. Lots easier, less messy, but it prolly doesn't meet anyone else's criteria.

YMMV

Dennis

 

[savagedasher]

My pet way will be on the market soon starting with 6MM then 30 Cal soon after. It doesn't use the total case capacity just useable capacity. it will be done off the shoulder so you don't have to trim the cases exact. Getting 100% repeat with.01 GR. Larry

 

[Capt. Oblivious]

I weigh the empty fired brass on my electronic scale, fill the piece off brass with water to the top and weigh again. Difference between the 2 is my internal capacity

 

[carl1575]

Thanks guys, I will try both and I am looking forward to what Savagedasher has up his barrel. Carl in Yakima

 

[22BRGUY]

Might want to add a couple drops of alcohol to the water to break or negate the surface tension so it doesn't "bubble up" at the case mouth for added accuracy.

 

[savagedasher]

Might want to add a couple drops of alcohol to the water to break or negate the surface tension so it doesn't "bubble up" at the case mouth for added accuracy.

The bubble in the case is not the big problem. On top is and any loss down the outside give big errors. Powder sounded great till I found out how it was put in a could change the weigh as much as water. Any OAL difference changed the results.
What I have works off the shoulder. Larry

 

[jlow]

Larry - Bubble means air, air means no liquid and so that will give you an inaccurate read on the weight i.e. volume.

OP - You can do this anyway you think is accurate. It is not hard if you have fine motor skills and know what you are doing. There are lots of detail description on how it should be done on the board, do a search and read up on it, then come back with questions.

Whatever you do, test your method BEFORE you go charging down the road doing measurements on different cases and come up with a conclusion. You have to be able to reproducibly measure a single case over and over again with variations you can live with for your purpose. For example, if you are measuring volume for QL, your errors will go into what the result the machine will spit out - the old saying "garbage in garbage out" applies here.

If you are trying to see if case volume is related to case weight, you measurement variations will need to be significantly less than the variation in your case volume or none of your data will mean anything.

 

[savagedasher]

Larry - Bubble means air, air means no liquid and so that will give you an inaccurate read on the weight i.e. volume.

OP - You can do this anyway you think is accurate. It is not hard if you have fine motor skills and know what you are doing. There are lots of detail description on how it should be done on the board, do a search and read up on it, then come back with questions.

Whatever you do, test your method BEFORE you go charging down the road doing measurements on different cases and come up with a conclusion. You have to be able to reproducibly measure a single case over and over again with variations you can live with for your purpose. For example, if you are measuring volume for QL, your errors will go into what the result the machine will spit out - the old saying "garbage in garbage out" applies here.

If you are trying to see if case volume is related to case weight, you measurement variations will need to be significantly less than the variation in your case volume or none of your data will mean anything.

Well aware of the air bubble. but that is minor to the bubble on the top .Any excess that runs down the case is even a bigger problem. What I have isn't for QL reference.
What I have give you a accurate reference to useable capacity. It repeats 100% of the time with in + or - .o1 Grains. as good as the scale I use.. Larry

 

[jcampbellsmith]

I just went on line to see how to do it, after 17 different ways my eyes were starting to cross and my mind was going numb, I went to my Ken Waters books, he has lots of examples case weight, water capacity, I couldn't find how he did it. Do one of you guys[Pet Way] of doing it, that a OLD car salesman can understand, Carl in Yakima

I use sugar. Sweet. JCS

 

[jlow]

Larry - Bubble means air, air means no liquid and so that will give you an inaccurate read on the weight i.e. volume.

OP - You can do this anyway you think is accurate. It is not hard if you have fine motor skills and know what you are doing. There are lots of detail description on how it should be done on the board, do a search and read up on it, then come back with questions.

Whatever you do, test your method BEFORE you go charging down the road doing measurements on different cases and come up with a conclusion. You have to be able to reproducibly measure a single case over and over again with variations you can live with for your purpose. For example, if you are measuring volume for QL, your errors will go into what the result the machine will spit out - the old saying "garbage in garbage out" applies here.

If you are trying to see if case volume is related to case weight, you measurement variations will need to be significantly less than the variation in your case volume or none of your data will mean anything.

Well aware of the air bubble. but that is minor to the bubble on the top .Any excess that runs down the case is even a bigger problem. What I have isn't for QL reference.
What I have give you a accurate reference to useable capacity. It repeats 100% of the time with in + or - .o1 Grains. as good as the scale I use.. Larry

Larry – excess that runs down the case can be a big problem but that really depends on the volume. Obviously if a significant volume runs down the case, it will be weight by the balance as case volume which you don’t want. The same could be said for bubbles depending on how many and their size since usually some of the volume of the bubble is under water and so takes up volume. The difficulty is in both cases, we are talking generalities. Both can have some or significant effect depending on volume. It is more correct to say that you want neither for accurate case volume. That is for the OP.

As for you, if it is reproducible you are GTO.

 

[savagedasher]

Any thing that isn't internal has effect on the volume. My process take some of the neck volume away but the checked inter always is the same. My stop is off the shoulder of the case Works like a head space gauge only the case shoulder the distance. Larry

 

[Brians356]

Read my H2O method comments here:

http://forum.accurateshooter.com/index.php?topic=3864488.msg36520146#msg36520146

In particular the part about the flat meniscus forming a perfect mirror.

There are plenty of other ideas in the thread as well.

I'm curious how you plan to use the case capacity. QuickLoad? Culling for batch uniformity? Comparing different manufacturer's cases?

 

[savagedasher]

Read my H2O method comments here:

http://forum.accurateshooter.com/index.php?topic=3864488.msg36520146#msg36520146

In particular the part about the flat meniscus forming a perfect mirror.

There are plenty of other ideas in the thread as well.

I'm curious how you plan to use the case capacity. QuickLoad? Culling for batch uniformity? Comparing different manufacturer's cases?

Go back and read I said what It DOES NOT have any reference to QL .
What I do Always give me the same results.+ or - one tenth. With is the same Error of the scale I use. Larry

 

[carl1575]

To answer Brians356 question what am I going to us it for- comparing different manufactures cases for a new 223AI. Brian I bought some thing from you several months ago, scope - brass ? something. I am the old VW- Porsche mechanic with Lew Florence race car team. I knew you were a Porsche pusher from your 356 handle. Thanks for all the in put . Carl in Yakima

 

[BillPa]

To answer Brians356 question what am I going to us it for- comparing different manufactures cases for a new 223AI. Brian I bought some thing from you several months ago, scope - brass ? something. I am the old VW- Porsche mechanic with Lew Florence race car team. I knew you were a Porsche pusher from your 356 handle. Thanks for all the in put . Carl in Yakima

Well, seeing you're an old VW-Porsche'sha ( ;D) mechinnick then you well know why oil (we used thinned mineral) is used to CC heads. It fills ALL the space in the chamber the same as the gases do when gasoline or other fuels are burned. Its no different measuring interior case capacity with water w/ a drop of soap to break it's surface tension.
BTW, I had a '65 bug w/built 356 motor and a '69 912 ..that was until I said "I do" ;D ( She did let me keep my '70 Ghia though ;D)

Bill

 

[savagedasher]

What is cc heads? :-[ Many here don't understand what a head even look like. And what cc it does. Only skinned knuckles and dirty finger nail old men. And real Engines do lay flat. ;D ;D
Larry

 

[BillPa]

What is cc heads?
Larry

Measuring the volume of the combustion chamber(s) of a cylinder head in "Cubic Centimeters" of a liquid. Why a liquid? Because it would conform and fill the chamber the same as when the fuel is ignited, the same as when the gases of the powder burn will fill a case, flash hole length included.
A good demo. https://www.youtube.com/watch?v=V7V40ZWNgCo


Bill