H20 Capacity Help

[savagedasher]

When checking water capacity the primer pocket has always ben a problem. Here is a easy fix.
Take your spent primers and put them in bottom side up. Larry

 

[jlow]

I use the 21st Century Primer Pocket Plug for H20 Weighing. Was skeptical at first but have found them handy and durable - makes the job easier. Save having to prime and deprime, they just plug in and pull off.

http://www.21stcenturyshooting.com/Primer_Pocket_Plugs.php

 

[Brians356]

When checking water capacity the primer pocket has always ben a problem. Here is a easy fix.
Take your spent primers and put them in bottom side up. Larry

I've always just used a spent primer reseated the normal way, and never had one leak, or not want to seat easily. What problem have you experienced?

 

[savagedasher]

When checking water capacity the primer pocket has always ben a problem. Here is a easy fix.
Take your spent primers and put them in bottom side up. Larry

I've always just used a spent primer reseated the normal way, and never had one leak, or not want to seat easily. What problem have you experienced?

I have had a bad reading from some cases that had fluid in the primer pocket. When I re check with the primer in reverse I got the same reading every time. Larry

 

[Brians356]

When checking water capacity the primer pocket has always ben a problem. Here is a easy fix.
Take your spent primers and put them in bottom side up. Larry

I've always just used a spent primer reseated the normal way, and never had one leak, or not want to seat easily. What problem have you experienced?

I have had a bad reading from some cases that had fluid in the primer pocket. When I re check with the primer in reverse I got the same reading every time. Larry

Fair enough. I would have expected water to get through the flash hole every time. But assuming it doesn't always, is there enough room for water in that pocket (occupied by a spent primer) to not be lost in the noise of the case-to-case variation?

Also, I believe the published H2O) capacity figures (as varying as they are) do include that water in the primer pocket.

As long as you are only comparing cases for consistency within a lot you have, and not comparing your capacities to someone else's published figures, then probably the smartest approach is to reverse the primers as you described.

 

[Travelor]

Seat a spent primer backwards.

 

[jlow]

When checking water capacity the primer pocket has always ben a problem. Here is a easy fix.
Take your spent primers and put them in bottom side up. Larry

I've always just used a spent primer reseated the normal way, and never had one leak, or not want to seat easily. What problem have you experienced?

I have had a bad reading from some cases that had fluid in the primer pocket. When I re check with the primer in reverse I got the same reading every time. Larry

I used to worry about this space inside the primer – I don’t anymore. When I first got the 21st Century Primer Pocket Plug, the very first thing I tested was whether the soild plug gives me different case volume than a spent primer – it did not. I am sure the volume is actually different but you just cannot detect that small volume difference with our methods.

FWIW, for those who are even more super anal about this stuff than me ;D, keep in mind that a spent primer has less “stuff” in it than a new unfired primer…

 

[Brians356]

I'd still like to know why the OP felt there was a problem. But perhaps the problem turned out not to be.

 

[jlow]

I frankly don’t think the OP had a problem. ;D He was not asking for help, just posting a “helpful” tip for whoever was interested.

 

[Brians356]

I frankly don’t think the OP had a problem. ;D He was not asking for help, just posting a “helpful” tip for whoever was interested.

With all due respect, the OP is at the top of the page, frankly you don't have to look far:

"When checking water capacity the primer pocket has always been a problem."

Again: What's the "problem"?

 

[jlow]

No need to get into a debate, just a misunderstanding. I thought you meant that the OP was asking for help with a problem, the title make this a possible misintrepration. If what you mean is what problem his fix was for, I don’t know.

 

[C Valentine]

Have lathe, will travel...I just turned a small 3/4" disk from soft plastic that has a little nub the size of the primer pocket in the center of it. Works great and holds the case securely upright on the scale.

 

[jlow]

But is the fit tight enough to keep the rubbing alcohol in? FWIW, the 21st Century Primer Pocket Plug has a small O-ring in that area to keep any fluid from leaking out.

 

[C Valentine]

Just tried it and yes it does...it's a bit of a rubbery type plastic so it seals well, as does one made of Azec. No doubt that the 21st Century one works well...and had I thought of it when I ordered my Concentricity gauge I would have ordered one. That must be a tiny little O-ring! But, since this shooting thing has taken over my life, I have to find some justification for the two lathes in my workshop!
Now that leads to my question, since alcohol is apparently lighter by volume than water. With 50% isopropyl alcohol I can fill a given .223 case to 29.4g (level with top of case). I can fill the same case with 30.8g of water. Both repeatable. What's the advantage of using alcohol (other than its evaporative properties) and how do you translate that to grains of water for use in something like Quickload?

 

[Brians356]

Just tried it and yes it does...it's a bit of a rubbery type plastic so it seals well, as does one made of Azec. No doubt that the 21st Century one works well...and had I thought of it when I ordered my Concentricity gauge I would have ordered one. That must be a tiny little O-ring! But, since this shooting thing has taken over my life, I have to find some justification for the two lathes in my workshop!
Now that leads to my question, since alcohol is apparently lighter by volume than water. With 50% isopropyl alcohol I can fill a given .223 case to 29.4g (level with top of case). I can fill the same case with 30.8g of water. Both repeatable. What's the advantage of using alcohol (other than its evaporative properties) and how do you translate that to grains of water for use in something like Quickload?

Who uses part alchohol, and why? "Capacity H2O" has been the simple standard forever. And why invent a substitute "plug" when a spent primer, seated normally, works fine, and has also been the standard forever. Are we inventing new problems to solve, out of sheer boredom? (I'll throw in the "problem" of drying water out of cases, too - unless you absolutely must load the cases mere minutes after measuring their capacities.)

With all due respect, you understand. I'm truly interested in knowing what problems these measures are trying to solve.

 

[C Valentine]

I don't use alcohol but just wondered why some others apparently did when the standard is H2O. For me, its just easier and quicker to use a plug that I can just pull in and out rather than fumbling with getting a spent primer back in place and then having to knock it out again. To each his own!

 

[savagedasher]

Case length and the bubble of water has effect on the reading you get. Water can also have air bubbles on the sharp corners and the primer hole.
Alcohol gives me the best reading. Reason being it is easy to dry up the case from the excess running out.
I DON'T check the case capacity for QL .
I know .02 of water in my case is Equal .01 gr of powder,
.01 of powder difference is 500 PSI And 8' difference in speed.
I did the ball powder thing . That didn't work,
The reason I check case capacity is to lower my ES and help with vertical at long yardage.. Larry

 

[Brians356]

I don't use alcohol but just wondered why some others apparently did when the standard is H2O. For me, its just easier and quicker to use a plug that I can just pull in and out rather than fumbling with getting a spent primer back in place and then having to knock it out again. To each his own!

Fair enough on the plug, as long as it doesn't protrude and prevent the case free standing on it's base in the scale's pan. For myself, priming and depriming are so easy, it's not worth my trouble.

As for the alcohol part: Plain water's meniscus is no problem, you just add tiny drops (I use a small model builder's superglue pipette) until the top of the water forms a flat mirror surface. It's so easy, I can't believe alcohol makes it any easier - and with 100% H20 you don't have to do any volumetric conversion, and can compare directly to various published references. But for those who crave "more complex": Work out!

For air bubbles, I tap the case a few times just before it is full. But I think the problem of bubbles is overstated.

"How'd you lose that 600-yard match?"
"I forgot to account for air bubbles."
"Come again?"

 

[C Valentine]

Brian, it's very stable...the nub is part of a flat disk.

I think if Spring doesn't come soon all of us are going to go nuts from cabin fever! LOL For those who already are and have become completely anal, I wonder what the difference in weight is between 50%, 70% and 90% alcohol? ;D ;D ;D :

 

[C Valentine]

Sorry jlow, yes I did, but not quite closely enough. Thank you for the detailed explanation. I think I will just stick to water for now. There is a whole bunch of stuff I need to put a higher priority on...like time behind the trigger, learning to read wind and mirage, etc. Heck I never even thought about grains of water capacity until I started using QL and it asked for it, then I started playing around with the effects of small capacity changes and noting the difference between brands of cases, fired and unfired, etc. and was frankly quite surprised at the differences. Good stuff to explore when I cant shoot!