Case capacity

[Tridog]

 I just received my new Lapua brass,  just curious to see what the difference was on the case capacity between my Hornaday brass and my Norma brass,  have been loading for about 30 years and I've never used water in my cases doesn't seem like you would get very good velocity out of it ,  so I filled  The cases with powder and checked the capacity filled to the top.                 Lapua (new) 49.3 hrs.                                         Honaday  both new and fired , 50.65 grs  average                                                                 Norma fired 51 grs  average                                Now you have some useless information!!lol!!

[Oryx]

What powder?  There is a ton of variables in powder, and the method of loading powder can affect the capacity. 

[jvw2008]

the method of loading powder can affect the capacity.

I don't understand.

[Maverick]

I don't understand.

For one, I use a drop tube when loading my BPCR cases with black powder.
A drop tube allows a more consistent powder drop allowing more powder to occupy the case capacity due to alignment of powder granules.
Here's a pic of my BP drop tube:


 

[Oryx]

Mavericks post regarding a drop tube is a great example.  As the powder goes into the case it won't always load uniformly.  The drop tube allows powder kernels to align better and enter the case more uniformly allowing a denser charge - like he said!
Tamping the case can also create capacity if the powder is not sitting well and voids exist. 
When measuring internal case capacity water will be more consistent and accurate.

[jvw2008]

Mavericks post regarding a drop tube is a great example.  As the powder goes into the case it won't always load uniformly.  The drop tube allows powder kernels to align better and enter the case more uniformly allowing a denser charge - like he said!
Tamping the case can also create capacity if the powder is not sitting well and voids exist. 
When measuring internal case capacity water will be more consistent and accurate.

Your last statement is correct. Water doesn't compress, therefore the measured case capacity is the actual case capacity. When compressing powder into the case, you are not changing case capacity, you are simply packing more powder into the same capacity. There is definitely a little bit of semantics here because it could be said that compacting the powder forces the case to have a greater capacity to hold more powder. ? Not trying to give you a hard time here Ornx - I typed most of this with tongue in cheek! Just making the point that recorded and published case capacity is measured with water as the standard.

[Tridog]

 I think the powder that I used was 4831 shortcut it was some powder that I had pulled and discarded , all cases were filled the same way and tapped five times , I realize it's not science just trying to get an idea of how the Lapua  compared to what I have been using in the past !!

[Danbonzo]

Your last statement is correct. Water doesn't compress, therefore the measured case capacity is the actual case capacity. When compressing powder into the case, you are not changing case capacity, you are simply packing more powder into the same capacity. There is definitely a little bit of semantics here because it could be said that compacting the powder forces the case to have a greater capacity to hold more powder. ? Not trying to give you a hard time here Ornx - I typed most of this with tongue in cheek! Just making the point that recorded and published case capacity is measured with water as the standard.

Correct. Period.

[Oryx]

Your last statement is correct. Water doesn't compress, therefore the measured case capacity is the actual case capacity. When compressing powder into the case, you are not changing case capacity, you are simply packing more powder into the same capacity. There is definitely a little bit of semantics here because it could be said that compacting the powder forces the case to have a greater capacity to hold more powder. ? Not trying to give you a hard time here Ornx - I typed most of this with tongue in cheek! Just making the point that recorded and published case capacity is measured with water as the standard.

No worries whatsoever.  I can't argue with anything you said !  I laughed when I read it and then read my statement about "creating" capacity... good laugh and fair correction!

[dadajack]

I just use a fine ball powder to get a rough estimate. Load a used primer in backwards and fill the case to the brim, skim the top, and measure the combined weight. I get the same reading every time I do this with the same case, so I think it is pretty good. Not as accurate as water, but if W296 don't flow like water, I don't know what does.

[Oryx]

Powder can give you relative capacities, but as mentioned earlier, water is the standard for comparison due to consistency. 

Love W296 though in both my 44 mag and 300BLK supersonic loads!

[dadajack]

I use a lot of W296, Lil'Gun, IMR 4227 and 2400. I haven't tried the 1680 in handgun carts, but it's so good in the 300 BLK, I just use it for that, subs anyway.

[Cold Trigger Finger]

I use H110  ;-)  :-)

[Cold Trigger Finger]

 No, water is the way to go. For sure. But I have done the same thing. Gives me an idea of what to expect. Some day I hope to have a nice reloading room. But for now its a 3 1/2 x 7' space . Partly shared with the pantry.
 Need a lot more space for annealing and casting from ingots. Gotta keep the heat away from the stuff that goes BOOM.