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Rifles, Reloading, Optics, Equipment
Rifles, Bullets, Barrels & Ballistics
Hammer Bullets Pressure Testing Results
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<blockquote data-quote="RockyMtnMT" data-source="post: 2830651" data-attributes="member: 7999"><p>Here is the remainder of the email chain.</p><p></p><p>Me asking permission to quote:</p><p></p><p>Hey Charlie,</p><p></p><p>That is terrific news in more than one way! For Ed this gives him the data that has been so illusive over so many hrs of trying to get QL to line up with results in the field. I can hear his excitement coming out of the computer! For me, this validates what we have been claiming for years and flies in the face of those who find the need to publicly call me out that this is not possible. With that said, may I quote you?</p><p></p><p>Steve Davis</p><p>Hammer Bullets</p><p>406-261-0010</p><p></p><p>Charlie's response:</p><p></p><p>Steve,</p><p></p><p>Sure, go ahead.</p><p></p><p>I am afraid there are "Experts" that do not have the credentials to be thought of as "Experts".</p><p>I am not an Expert, just a knowledgeable individual that tries to verify my thoughts on some subject.</p><p></p><p>GRT and QL has 2 lumped sum parameters (IP and Sebert for GRT, and Start Pressure and Weighting Factor). The defaults as expressed by both programs are simply averages. Anyone that thinks the Start Pressure and Weighting Factor can or would be the same cartridge to cartridge, and bullet to bullet, is simply fooling himself. </p><p></p><p>The problem arises when generating a Simulation for Internal Ballistics is that the true value of those parameters are not directly measurable at any Reloader level of tools available. The designers of the software are aware of this, but they are also not able to measure these values. So what happens? They use an average value. Then when they develop a propellant model, it is calibrated to those default values. Then along comes Joe Reloader who's rifle is somewhat different than the barrels used to work up the propellant models, and he gets different outcomes. </p><p></p><p>Therefore, the simulation User thinks this software is completely useless. However, if the User is a bit knowledgeable, and realizes there are differences between barrels and bullets, and he can imagine in his mind what the differences may be, and project in his mind what the results might be, then he can make educated estimates. He then runs some test for velocity and adjusts things like the 2 lumped sum parameters, or the propellant models, or perhaps all three to bring the simulation into agreement with reality. At that Point the User can then pretty much rely on the simulation results if he changes things like bullets. A ladder test across 2 – 3 grains of propellant will show how well the propellant model tracks. </p><p></p><p>The big difference between GRT and QL is the Propellant models. GRT models were developed using User rifle reality data, and QL primarily uses data from Closed Bomb and Lab grade proof barrels made to very strict standards. Therefore QL will simulate better when using Lab Grade barrels than with Off the Shelf types. GRT works better with the Off the Shelf barrels, and therefore will usually not align well with published data that was taken in the Lab barrels. A propellant model developed for 50 to 60 grains of charge may not work well when used with a cartridge of 25 – 30 grain charge level as the penetration of the primer flash will be different amongst various other things.</p><p></p><p>The published data automatically contains a "Safety" factor as the Off the Shelf barrels will normally not produce pressures as high as the Lab barrels. This in not true 100% of the time as mistakes are made and published. I cannot tell you the number of times I have discovered transposed load data in various published documents. I can tell you that when I discover these transpositions (or other mistakes) it is the EU propellant companies that take the most effective action to verify and correct the published data in a very timely manner. Vihta Vuori is the best for this, and the USA manufacturers are the worst. There are some loads using Varget that will not even fit in the cases specified and over flow the case mouth. </p><p></p><p></p><p></p><p>Project Relations</p><p>Gordons Reloading Tool</p><p>Berlin, Germany</p><p><a href="mailto:charlie@grtools.de">charlie@grtools.de</a></p><p><a href="https://www.grtools.de/" target="_blank">https://www.grtools.de/</a></p><p>[MEDIA=youtube]NJt7vFWH3tQ[/MEDIA]</p><p><a href="https://discord.com/invite/3FEYWG4" target="_blank">https://discord.com/invite/3FEYWG4</a></p></blockquote><p></p>
[QUOTE="RockyMtnMT, post: 2830651, member: 7999"] Here is the remainder of the email chain. Me asking permission to quote: Hey Charlie, That is terrific news in more than one way! For Ed this gives him the data that has been so illusive over so many hrs of trying to get QL to line up with results in the field. I can hear his excitement coming out of the computer! For me, this validates what we have been claiming for years and flies in the face of those who find the need to publicly call me out that this is not possible. With that said, may I quote you? Steve Davis Hammer Bullets 406-261-0010 Charlie's response: Steve, Sure, go ahead. I am afraid there are "Experts" that do not have the credentials to be thought of as "Experts". I am not an Expert, just a knowledgeable individual that tries to verify my thoughts on some subject. GRT and QL has 2 lumped sum parameters (IP and Sebert for GRT, and Start Pressure and Weighting Factor). The defaults as expressed by both programs are simply averages. Anyone that thinks the Start Pressure and Weighting Factor can or would be the same cartridge to cartridge, and bullet to bullet, is simply fooling himself. The problem arises when generating a Simulation for Internal Ballistics is that the true value of those parameters are not directly measurable at any Reloader level of tools available. The designers of the software are aware of this, but they are also not able to measure these values. So what happens? They use an average value. Then when they develop a propellant model, it is calibrated to those default values. Then along comes Joe Reloader who's rifle is somewhat different than the barrels used to work up the propellant models, and he gets different outcomes. Therefore, the simulation User thinks this software is completely useless. However, if the User is a bit knowledgeable, and realizes there are differences between barrels and bullets, and he can imagine in his mind what the differences may be, and project in his mind what the results might be, then he can make educated estimates. He then runs some test for velocity and adjusts things like the 2 lumped sum parameters, or the propellant models, or perhaps all three to bring the simulation into agreement with reality. At that Point the User can then pretty much rely on the simulation results if he changes things like bullets. A ladder test across 2 – 3 grains of propellant will show how well the propellant model tracks. The big difference between GRT and QL is the Propellant models. GRT models were developed using User rifle reality data, and QL primarily uses data from Closed Bomb and Lab grade proof barrels made to very strict standards. Therefore QL will simulate better when using Lab Grade barrels than with Off the Shelf types. GRT works better with the Off the Shelf barrels, and therefore will usually not align well with published data that was taken in the Lab barrels. A propellant model developed for 50 to 60 grains of charge may not work well when used with a cartridge of 25 – 30 grain charge level as the penetration of the primer flash will be different amongst various other things. The published data automatically contains a "Safety" factor as the Off the Shelf barrels will normally not produce pressures as high as the Lab barrels. This in not true 100% of the time as mistakes are made and published. I cannot tell you the number of times I have discovered transposed load data in various published documents. I can tell you that when I discover these transpositions (or other mistakes) it is the EU propellant companies that take the most effective action to verify and correct the published data in a very timely manner. Vihta Vuori is the best for this, and the USA manufacturers are the worst. There are some loads using Varget that will not even fit in the cases specified and over flow the case mouth. Project Relations Gordons Reloading Tool Berlin, Germany [EMAIL]charlie@grtools.de[/EMAIL] [URL]https://www.grtools.de/[/URL] [MEDIA=youtube]NJt7vFWH3tQ[/MEDIA] [URL]https://discord.com/invite/3FEYWG4[/URL] [/QUOTE]
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Hammer Bullets Pressure Testing Results
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