measuring water capacity- care to share your tricks?

[stool]

ok bu tit has no use in the real world of ballistic software, so not much use in my opinion.
the number relates to very little.
i'm sure it works

i'll bite...what does that do ???
give us some values to compare against published case volume....

would be neat if there was some relation to the real world...

all ears

Donovan taught me to check case capacity with H380 it is much easier.

If you're objective is to sort a group of cases by volume it's very effective. It's fast, sensitive, reproducible and there's no water or meniscus to deal with. The only relationship is comparing one case to the others which, if you're sorting a bunch of brass into uniform batches, is all you really care about.

 

[stool]

no some of us think the ENERGY used to expand that case has to be accounted for.
that the combustion chamber is not what you think it is if your calculations are based on AFTER YOU BURN SOME POWDER.

HAVE A GOOD DAY.

I like your in-site that it's the volume when the case expands against the chamber that matters. To many followers in this game and not enough thinkers. I wonder what they will think of our methods 25 years from now. Did you make the movie?

 

[jlow]

The choice of medium to measure volume is tricky. Of the ones mentioned, each has its own problem. Here is what I have found:

• Water – it wets your case but does not leave any significant residue when dried. Has high surface tension which means it has one of the worst meniscus problem.

• Rubbing alcohol – it also wets your case but dries just a bit faster, like water with no significant residue. Less surface tension and so less meniscus problem.

• Water with soap – It also wets your case but it does leave that soap residue which means you have to rinse it out well before use. Less surface tension like rubbing alcohol and so less meniscus problem.

• Gun powder like H380 – Does not wet your case or leave residue behind. No meniscus problem but its volume could be affected by packing and humidity.

 

[Killshot]

Good thread here........
Some questions/points;
As an F'er (not benchrest) we typically load 65-100 rounds in advance of a match and brass is normally processed all together and the cases are not kept in order after firing or during the cleaning and sizing process.
Noting case dimensions on the case will not survive my cleaning (SS media) so would one be looking at doing this before each loading? (That ain't happening on my bench)

It would also seem that the internal volume method would necessitate that every case be trimmed to the exact same length, yes?

When loading brass after internal capacity has been measured, what are some of your methods with regard to sequence? Lowest to highest or vice-versa?

Lastly, has anyone actually verified with a chrono the internal volume sorting led to lower spreads than that of brass that was not weighed?
Or determine if ES/SD spreads were lower than if the cases were just weight-sorted?

GIFs are terriffic.....

 

[stool]

ok...but measuring case volume is not just about sorting by volume, it is also used with software to load develop....the chrono data can then be used to backwards engineer computer data for more load development.

nothing wrong with your process, but unlike water volume, it stops at case volume for that powder.

The choice of medium to measure volume is tricky. Of the ones mentioned, each has its own problem. Here is what I have found:

• Water – it wets your case but does not leave any significant residue when dried. Has high surface tension which means it has one of the worst meniscus problem.

• Rubbing alcohol – it also wets your case but dries just a bit faster, like water with no significant residue. Less surface tension and so less meniscus problem.

• Water with soap – It also wets your case but it does leave that soap residue which means you have to rinse it out well before use. Less surface tension like rubbing alcohol and so less meniscus problem.

• Gun powder like H380 – Does not wet your case or leave residue behind. No meniscus problem but its volume could be affected by packing and humidity.

I should add that in general, powder works really well for me. Here is a graph from a study where I measured the weight of 25 pieces of LC09 brass and plotted it against the average weight of two TAC powder filling in the same case. Correlation coefficient of 0.94 (1 is perfect and 0 is absolutely no correlation).

 

[Webster]

I don't think German Salazar and John Whidden determine volume when doing case prep. I can not find their write up to verify it. I have been doing failure analysis for 45 years, I like to see something that looks like proof and not opinions. It would be nice if someone could sort cases by weight, then measure the volume. Keep track of the cases then shoot them over a chronograph and make a table showing weight, volume and velocity. Would the data show a correlation between any of the the data and velocity and extreme spread? I cannot believe people are going through these rituals without trying to prove it's value. Someone must have done this without widespread sharing the info with others.

Is Quick Load really a useful tool. You cannot believe how difficult it is to correlate 15 variables. Three or 4 are difficult. I would think that anyone that shoots in competition would know what powder and bullets are working well in competition. You still have to shoot the various loads to test them.

 

[stool]

i do not believe german shoots competitive benchrest at any distance...whidden may.
the further you shoot the more the little things count.
if you shoot a 2moa 10 ring..very little is required for load development.
if you are shooting 1000 yds where the record is just under 1.5 inches( as in 0.14xxmoa) everything counts.
go look at short range benchrest....more and more guys are using precision electronic scales( .02/.01 accuracy)

i reverse engineered john feamster's shooting in his book "black magic". he shot one lot of 500 pc of win brass..unsorted.
i bought the brass from that he used in the book and weight sorted it. while most was in the middle of a bell curve the ends of the curve were long and easily explained the flyers he would get. i don not have access to that data right now but it was not pretty.


quick load is a tool and only as good as the user.

I don't think German Salazar and John Whidden determine volume when doing case prep. I can not find their write up to verify it. I have been doing failure analysis for 45 years, I like to see something that looks like proof and not opinions. It would be nice if someone could sort cases by weight, then measure the volume. Keep track of the cases then shoot them over a chronograph and make a table showing weight, volume and velocity. Would the data show a correlation between any of the the data and velocity and extreme spread? I cannot believe people are going through these rituals without trying to prove it's value. Someone must have done this without widespread sharing the info with others.

Is Quick Load really a useful tool. You cannot believe how difficult it is to correlate 15 variables. Three or 4 are difficult. I would think that anyone that shoots in competition would know what powder and bullets are working well in competition. You still have to shoot the various loads to test them.

 

[CatShooter]

<snip>
I like to see something that looks like proof and not opinions. It would be nice if someone could sort cases by weight, then measure the volume. Keep track of the cases then shoot them over a chronograph and make a table showing weight, volume and velocity. Would the data show a correlation between any of the the data and velocity and extreme spread? I cannot believe people are going through these rituals without trying to prove it's value. Someone must have done this without widespread sharing the info with others.

<snip>

Webster... you are being a poopie head... the rituals ARE are important.

Much of what you read on BR pages, is not real information derived from real tests, or (God forbid) double blind tests - it is anal compulsive, made up theories that don't hold water when held up to the sunlight.

 

[Webster]

At least I don't put girlie pix on the website.

 

[CatShooter]

At least I don't put girlie pix on the website.

I think you missed the point I was making - I was agreeing with you.

As to girlie pix - oh golly, what a terrible thing to expose grown men to.

 

[Webster]

Thanks for the clarification. I would like to see someone put up on the website a detailed description of how burn rate is determined. I am still searching the net for it. I found it once several years ago. I think there is a big misunderstanding off how it is done. The burn rate charts we see are only a ranking determined under conditions that have nothing to do with a rifle or rifle cartridge.

 

[stool]

are you talking about closed bomb testing ??

Thanks for the clarification. I would like to see someone put up on the website a detailed description of how burn rate is determined. I am still searching the net for it. I found it once several years ago. I think there is a big misunderstanding off how it is done. The burn rate charts we see are only a ranking determined under conditions that have nothing to do with a rifle or rifle cartridge.

 

[Webster]

Yes

I found the description of burn rate determination from an Army Report. Read and enjoy. Everyone keep opinions to yourself. I am not in the mood for anal retentive comments.


Do a Google search for "Burn Rate Bomb Test"

Click on the below site:

The Burning Rate Behavior of Pure Nitrocellulose Propellant ...
www.dtic.mil/cgi-bin/GetTRDoc?AD=ada261009‎
by FW Robbins - ‎1993 - ‎Cited by 2 - ‎Related articles
Both closed bomb and strand burning rate tests were included in the test program. Production, tests, and analysis were performed at the Naval Ordnance Station ...

 

[Raythemanroe]

Girly pics,

 

[Killshot]

Girly pics,

I know, right? (and GIFs are better than stills )

Let us not foget the other joys in life....

 

[bigedp51]

Girly pics,

I know, right? (and GIFs are better than stills )

Let us not foget the other joys in life....

I guess you didn't know that CatShooter's greatest joy in life is listening to Rap music when he reloads.

 

[CatShooter]

I guess you didn't know that CatShooter's greatest joy in life is listening to Rap music when he reloads.

Actually I have a TV over the loading bench (really) and I watch the history channel.

 

[wolfman]

Thanks Gents- I certainly appreciate the effort you have put into your explanations. I guess I should have explained my motivation at the beginning. I don't have a copy of Quickload, but I've got a new 6mm-250 AI that doesn't seem to want to shoot with the standard, go-to powder, so I asked a buddy to run the numbers, in hopes for finding something else that might work. He responded with a request for water capacity, and you all know the rest of the story.

and yeah, GIF's are great.

 

[jlow]

QuickLoad is expecting the case to have been fired at least once without sizing. QuickLoad also assumes you have filled the case to overflowing (a convex meniscus). Catshooter and others are correct in that leveling the water at the case mouth gives you a more accurate representation of the true volume but to get the best results from QuickLoad I would do it their way.

To get a more consistent meniscus it's helpful to put a water barrier on the case mouth. Just a smidgen of stopcock grease works great. If you don't have any stopcock grease Imperial sizing die wax will work. Just the end of the neck, not inside or outside.

Weigh a fired, unsized case with the spent primer in place.

Fill the case with plain old water at room temperature. The way I fill it is with a syringe with a thin flexible plastic tube attached. This way the water can be added without mixing air in with it.

Fill it until it almost overflows as in a big humped up meniscus (it gets bigger and higher with the grease on the end). Kind of like plumbing where you tighten it until just before it breaks.

Weigh the filled case and subtract the empty weight.

I actually do three at a time and take the average. If the case OAL is consistent your results should be within +/- 0.2 grains. It doesn't sound especially precise but with medium sized cases you may find your results are different than the QuickLoad defaults by a couple grains or more so you're way ahead of the game.

I just got QL in the mail and have been looking through it. I am not seeing where "QuickLoad also assumes you have filled the case to overflowing (a convex meniscus)." Can you point me to where this is?

Addendum: OK, looks like it is not in the instructions but in the label for the actual volume entry where it says "Maximum Case Capacity, overflow".... I wonder why they do it this way? Does not seem like the most accurate way to do this?

 

[Webster]

RE: GIF pix

I think you need the water displacement volume on this one. Average the two values.