Measuring case capacity (water)

[n4ue]

Hi. Time for a dumb question. I can't seem to find an answer, and there may NOT be one! ha ha

I have tried using water to measure the relative case capacity of some new ctgs. before and after fire forming.

Question: Is there something I can do to reduce the surface tension of the water? I 'think' that there are air bubbles in the primer pocket or in the shoulder of the AI bases. I noticed a large delta in case weight that was inconsistent even using the same case.

Distilled, de-ionized water??????

What's the correct method?

thank you!

ron

[fgw_in_fla]

Add a drop of dish soap to the water.

[Balljoint]

Found this in my tickle file 308 Mil Cases hold 56 gr. water and Factory Cases hold 58 Gr., 308 case length 2.015

[n4ue]

Thanks Frank. I just knew there was a simple solution. Today, I remembered (?) that in some of my hot rods and a drag car, I had used Red Line "Water Wetter". I think I have some, somewhere......... This will give me something to experiment with until I can pick up my new rifles Sat......
Thanks again.

ron

[fgw_in_fla]

No problem.

Probably the only class I showed up for on a regular basis in school.

Science.

[n4ue]

Tequila works.

My last gf had 29 tattoos. When someone would ask her what made her get them, her answer was always:

Tequila!
My buddy just came back from Cabo St. Lucas and brought me back a bottle of Sammy Hagar's, Cabo Wabo, and matching T-shirt.
What a pal!

ron

[Savage6x284]

Add a drop of dish soap to the water.

Frank nailed it!

[Jimmy21]

How do you keep the water from coming out the primer pocket? How do you guys go about it? Squirt water from a syringe in to the case and then dump the water in to the scale, then dump out the scale and dry with a towel and repeat?

[CharlieNC]

Fill it with a primer; and be sure the case is sized.

[Jimmy21]

Wouldn't that ruin the primer?

[Savage6x284]

Use a fired primer either inserted after sizing or just size the case without the decapping pin.

My procedure is to prepare the case as above and put the empty case on the scale. Tare the scale if using an accurate, sensitive digital scale or note the weight if using a mechanical scale. Fill the case with water using a syringe, baster or whatever making sure not to get water drops on the outside of the case. If you do get water on the outside it'll need to be wiped off with a paper towel.
Weigh the filled case and subtract the empty weight from the filled weight.
The resulting number is the case capacity in grains of water.