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Posted: 1/25/2014 4:27:31 AM EDT
[#1]
Mind enlightening me on what a VMD is?
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Posted: 1/25/2014 4:42:02 AM EDT
[#2]
I believe it means volumetric displacement. The units of measurement are cc/gr.
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Posted: 1/25/2014 7:47:11 AM EDT
[#3]
It's much easier to just measure powder in grains, it's what most reloaders do.
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Posted: 1/25/2014 12:36:05 PM EDT
[#4]
Look on manufactures website Accurate
 You probably loading with a Lee
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Posted: 1/25/2014 3:23:04 PM EDT
[#5]
Lots of mind-readers in here. Sorry fellas, I'm not trying to load using CCs. Did you really think I'm such a noob?
I'm trying to narrow down powders to load with based on % of the case it fills. It's simple geometry to determine case volume, but powder volume isn't as easy. These numbers are usually published, but aren't in either of my lists. From there, I'm comparing my calculations with QuickLoad's calculations. It's a complicated, but interesting, process. 
So...back to my original question...
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Posted: 1/25/2014 3:25:33 PM EDT
[#6]
Quote HistoryThanks! 1 down, 3 to go. 
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Posted: 1/25/2014 7:19:03 PM EDT
[#7]
Quote HistoryQuoted: Lots of mind-readers in here. Sorry fellas, I'm not trying to load using CCs. Did you really think I'm such a noob? I'm trying to narrow down powders to load with based on % of the case it fills. It's simple geometry to determine case volume, but powder volume isn't as easy. These numbers are usually published, but aren't in either of my lists. From there, I'm comparing my calculations with QuickLoad's calculations. It's a complicated, but interesting, process. So...back to my original question... These will be the slow burning, for this cartridge, powders. Slow powders will fill a case up and some of them will be compressed. Over 100% load density. Also Nosler manuals list load density for their loads. Study powder burn rate charts and read the powder descriptions in loading manuals for more information.
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Posted: 1/25/2014 10:24:24 PM EDT
[#8]
The strange thing is there doesn't appear to be any mathematical correlation between the QL fill ratios (%) and the VMDs. I tried to do a back-calculation, but it just didn't end up between the next higher and lower options. The other difficulty is I was getting data for a certain velocity rather than max pressure, so the values aren't quite so easy to assess, but I see your point that when looking at Pmax charges, they larger are slower. Thanks.
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Posted: 1/26/2014 2:17:46 AM EDT
[#9]
What you are looking for is the "excluded volume". I forget the formula (age related) but is very simple to use.
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Posted: 1/26/2014 6:05:14 AM EDT
[#10]
Quote HistoryQuoted:
The strange thing is there doesn't appear to be any mathematical correlation between the QL fill ratios (%) and the VMDs. I tried to do a back-calculation, but it just didn't end up between the next higher and lower options. The other difficulty is I was getting data for a certain velocity rather than max pressure, so the values aren't quite so easy to assess, but I see your point that when looking at Pmax charges, they larger are slower. Thanks. There's not. The only place I've seen bulk density published is in Handloader magazine. Whether the author calculated the value or got it from the gunpowder seller I can't say. When I start loading a new gunpowder or a new cartridge, one step I document is the weight of a case full of each gunpowder that I want to use, just so I have some idea about the difference between typical charge weights and a full case. The most remarkably dense gunpowder I use is Longshot. When I started loading 28 gauge ammunition I had trouble with crimps due to the volume of gunpowder in the case. On the advice of an employee over at Olin, I tried Longshot, and it's perfect. Get a couple of pieces of lab equipment and a good scale and get busy. |
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Posted: 1/26/2014 3:51:10 PM EDT
[#11]
Veritas S63 is on the way. It's OOS right now, so backorder is about another month.
ETA: There's not [a correlation]? Not directly, but with known charge weights, fill % can be calculated from VMD and vice versa (as I'm sure you know). Maybe I forgot to mention I'm working with known charges. Still, like I meant to say, the VDM*charge/capacity and fill % aren't calculating to be equal when using quickload vs. standard geometry. |
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Posted: 1/27/2014 12:39:26 PM EDT
[#12]
I searched for about an hour for the others you needed just for the hell of it. Came up empty. Good luck.
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