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Rifles, Reloading, Optics, Equipment
Rifles, Bullets, Barrels & Ballistics
Experiment for quantifying lot to lot variations of powders
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<blockquote data-quote="Michael Courtney" data-source="post: 683248" data-attributes="member: 28191"><p>Wow, if this experiment was funded by a few hundred K and I had a graduate student, you have a whole PhD thesis written out there. You've got some interesting ideas, but really much more than the $1k or so and 100-300 shots that we like to see for a typical experiment. We like projects that can be written up in the space of a typical Precision Shooting article and digested in one sitting by a typical long range shooter with an interest in technical details, but not necessarily in possession of an engineering degree. We like to keep a project to one independent variable and save exploration of other variables for follow up studies.</p><p></p><p>We've also noticed that Precision Shooting and Varmint Hunter and other typical publication venues are occasionally willing to publish two part series, but are not usually willing to endure a thesis level exploration of a subject. PS has published two of our friction articles, and also published a two part series on bullet stability by Don Miller and myself. Varmint Hunter has published several of our ballistic coefficient articles, but has not yet responded favorably to a recent submission. Accurate Shooter sent a positive response to a submission on bullet weight variations, but they have not actually posted the piece. A thorough exploration is more likely to get done if a venue is willing to publish it.</p><p></p><p>A sample size if 10 will typically give a uncertainty in the mean velocity of 5 feet per second with Hodgdon Extreme powders and our current brass prep and barrel cleaning techniques. That is good enough to see if lot-to-lot variations are consistent with the claim of 8 fps or closer to Hodgdon's results for other brands. Reducing the uncertainty by a factor of 2 requires four times as many shots. 40 shots for each lot makes this a much more expensive and time consuming experiment, close to $4k and over 1000 shots. </p><p></p><p>Would you rather see the same cartridge and powder in three different rifles, or different powders and cartridges in three different powders? I think the initial study would do better to study five or six different powders in different cartridges and rifles. Once these results are in hand, then they would better inform the most interesting avenues to proceed in future studies.</p><p></p><p>So maybe the question to ask is, of all the possible studies, what would be the best use of the first 200-300 shots, and why?</p></blockquote><p></p>
[QUOTE="Michael Courtney, post: 683248, member: 28191"] Wow, if this experiment was funded by a few hundred K and I had a graduate student, you have a whole PhD thesis written out there. You've got some interesting ideas, but really much more than the $1k or so and 100-300 shots that we like to see for a typical experiment. We like projects that can be written up in the space of a typical Precision Shooting article and digested in one sitting by a typical long range shooter with an interest in technical details, but not necessarily in possession of an engineering degree. We like to keep a project to one independent variable and save exploration of other variables for follow up studies. We've also noticed that Precision Shooting and Varmint Hunter and other typical publication venues are occasionally willing to publish two part series, but are not usually willing to endure a thesis level exploration of a subject. PS has published two of our friction articles, and also published a two part series on bullet stability by Don Miller and myself. Varmint Hunter has published several of our ballistic coefficient articles, but has not yet responded favorably to a recent submission. Accurate Shooter sent a positive response to a submission on bullet weight variations, but they have not actually posted the piece. A thorough exploration is more likely to get done if a venue is willing to publish it. A sample size if 10 will typically give a uncertainty in the mean velocity of 5 feet per second with Hodgdon Extreme powders and our current brass prep and barrel cleaning techniques. That is good enough to see if lot-to-lot variations are consistent with the claim of 8 fps or closer to Hodgdon's results for other brands. Reducing the uncertainty by a factor of 2 requires four times as many shots. 40 shots for each lot makes this a much more expensive and time consuming experiment, close to $4k and over 1000 shots. Would you rather see the same cartridge and powder in three different rifles, or different powders and cartridges in three different powders? I think the initial study would do better to study five or six different powders in different cartridges and rifles. Once these results are in hand, then they would better inform the most interesting avenues to proceed in future studies. So maybe the question to ask is, of all the possible studies, what would be the best use of the first 200-300 shots, and why? [/QUOTE]
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Experiment for quantifying lot to lot variations of powders
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