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Following this thread and being curious I decided to test the theory of filling a sized case with a bullet seated and filling the case with water through the primer hole. I weighed a case with seared 129 ablr bullet which I just received last week. Then bit of plumbers putty just big enough to seal the primer pocket and weighed all of it together and got 236.9 gr. Filling the case was challenging because I basically had to fill the primer pocket and push that small amoutnt in with a piece of wire. 10 min later it was filled. Sealing and weighing yielded 264.8. I pulled the plug and tried to add more water, resealed and reweighed. Same result at 264.8. One more time just to be sure and got the same weight.
So for me with a hornady case, 129 gr ablr bullet I get 27.9 gr of case space to be 100% full.
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TedBrewer5 Wrote:So for me with a hornady case, 129 gr ablr bullet I get 27.9 gr of case space to be 100% full.
You won't be able to enter that into Quickload and get a meaningful prediction. QL's case volume for SAAMI Grendel is 35.99gns of water.
QL instructions for measuring case capacity is for loads exceeding 30K lbs of pressure to use an unsized case. For loads below 30K use a sized case. In both cases ttimmed to 'specified length' and filled to 'overflow' - no bullet.
Trying to fill a case through a tiny primer hole with nowhere for the air to escape is hard core - My hat goes off to you.
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The Nosler measurement is with a bullet seated. I did some searching and found this explanation of how the info was used. These are 2 different explanations.
Quote:If you are using a system based on calculating pressure which is similar to the Powley Computer to calculate load and chamber pressure, that system uses the H2O capacity with the bullet seated in the case. Perhaps that is why Nosler uses that capacity?
Quote:Sorry to resurrect this but I knew I had read of the method Nosler uses and I found it with an explanation.
It's referenced in "Precision Shooting Reloading Guide" edited by Dave Brennan.pages 273 and 274. Comes originally from the 85% solution as a good starting point for the average rifle. I.e. A powder charge starting at 85% of a cartridges water capacity (with bullet) is a basic reloading principle. He broadens this out w further explanation as to powder efficiency, velocity etc.
Since these guys do/did Precision Rifle mag I figure they probably know what they're doing.
I'm sure a math whiz could take a full water measurement, compare it to Noslers number and work a percentage calculation to find that starting point. (I'm lazy, I let the computer figure it :grin: )
Anyhow, there's one point of reference on the water capacity with bullet.
FWIW.
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10-27-2021, 07:41 PM
(This post was last modified: 10-27-2021, 07:45 PM by Harpoon1.)
Klem Wrote:The Quickload program lists a default case capacity that is close to a Lapua case.
I size a few cases, insert a used primer to seal the hole and then weigh the case empty. Then fill the case carefully and tap to get rid of any bubbles and fill to the top. Run a straight edge across the top to remove the meniscus and take the average water weight of three or four of these.
Do you know how to/or why others (re manufacturers) calculate it for specific bullet weights? For example, Nosler gives a case capacity of 32 grns for the 90 grn Varmegeddon and then 28.7 grns for the 129/130 bullets?
I dont have QL, so, not sure why I should go to the trouble of finding the empty case volume if I cant easily adjust it for each bullet weight?
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Trying to fill a case through a tiny primer hole with nowhere for the air to escape is hard core - My hat goes off to you.[/QUOTE]
Klem,
It wasnt exactly fun doing it but it did shed some light on my future work up for the 129 gr ablr. It is so long that I knew capacity would be an issue. I prefer not to compress. I even did a vibratory settling test with 27 gr AR Comp to see how much room it yielded and found it settled the powder quite a bit
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Harpoon1 Wrote:Do you know how to/or why others (re manufacturers) calculate it for specific bullet weights? For example, Nosler gives a case capacity of 32 grns for the 90 grn Varmegeddon and then 28.7 grns for the 129/130 bullets?
I dont have QL, so, not sure why I should go to the trouble of finding the empty case volume if I cant easily adjust it for each bullet weight?
Harpoon,
I am sure QL and Nosler are doing the same thing; working out how much volume is left after a bullet has been seated. They go about it in different ways. Nosler seats a bullet and fills the case up with water from the base. Turning the bullet upside down and filling from the base, the obvious place would be the primer hole. You could also sacrifice the case by drilling a larger hole to make it easier.
Quickload works out the weight of water displaced by taking away an estimate of how much weight is displaced by a seated bullet. When you enter a new bullet QL wants to know the shape of the base, so the program can calculate the volume displaced for whatever OAL you enter.
It's the same thing; one actually does it while the other calculates it.
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Klem Wrote:Harpoon,
I am sure QL and Nosler are doing the same thing; working out how much volume is left after a bullet has been seated. They go about it in different ways. Nosler seats a bullet and fills the case up with water from the base. Turning the bullet upside down and filling from the base, the obvious place would be the primer hole. You could also sacrifice the case by drilling a larger hole to make it easier.
Quickload works out the weight of water displaced by taking away an estimate of how much weight is displaced by a seated bullet. When you enter a new bullet QL wants to know the shape of the base, so the program can calculate the volume displaced for whatever OAL you enter.
It's the same thing; one actually does it while the other calculates it.
Thanks for the thoughtful reply.
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I knew that I had read somewhere about another shooter that measured the water capacity of a case by seating the bullet. Here is how he explained it in the article. It was on page 26 under the heading "Building Handloads" in the 2019 Hodgdon Reloading magazine.
Quote:The most accurate method involves weighing a fired case, filling it with water, then pushing a bullet into the neck to the standard overall case length. After carefuly pulling the bullet out (and wiping any tiny drops from its surface into the case neck), the water filled case is then weighed, and the weight of the empty case is then subtracted.
He doesn't say whether he expands the neck until he can insert the bullet easily with his hand or if he uses a press and then pulls the bullet using his press. Seems like water would be coming out of the neck either way. Just another FYI.
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11-11-2021, 04:42 PM
(This post was last modified: 11-11-2021, 04:59 PM by Zeneffect.)
edit. ignore me, this is what happens when trying to read at 8:30am
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Zeneffect Wrote:edit. ignore me, this is what happens when trying to read at 8:30am
I am in the same boat as you. I reread his words and it seems he uses a fired case without resizing.
Quote:weighing a fired case, filling it with water, then pushing a bullet into the neck to the standard overall case length
