The Accurate Reloading Forums THE ACCURATE RELOADING.COM FORUMS Guns, Politics, Gunsmithing & Reloading Reloading Re: How do I figure out pressures?Go | New | Find | Notify | Tools | Reply | |
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Quote: No, but I can get a pressure gauge or transmitter calibrated and tracable to NIST. We do 5 point calibrations on commercial pressure transmitters here in our shop all the time. The setup is basically a calibrated set of weights, a piston, and a compressed nitrogen source. More weights on top of the piston means a higher pressure before the piston rises and begins to vent...and it is a .02% accuracy calibration when we are done with them. Just one example of an 'indirect' calibration, using mass to calibrate in PSI...we also use a calibrated decade box (resistance source for the not EE/instrumentation types) to do cal curves on RTD based temperature transmitters... | |||
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Quote: Perfect example! You know the area of the piston, the mass, g, etc., and get .02% calibration of PSI without a PSI reference. | |||
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Quote:Hey DJ, If I had said the example was "hypothetical", would it have been a proper question that could be answered then? If not, please create the question as it should have been and then provide the answer. Not at all trying to trick you or force you in a corner. My education and experience are telling me one thing, but it seems you, CDH and WildHog(love that handle) either: 1. Know something about this I don't know. Hey, explain it to me!!! 2. You all are sincere, but mistaken. (99.999999% chance  )3. Or you know as little about it as can be and are just wanting to aggravate an old man into a stroke or coronary or whatever mean thing you young whippersnappers are trying to do. (#3 is opting for the sympathy vote from the Rookies. ) | |||
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Quote: I wouldn't try to do that myself HC. Hey BTW, did you see where Saeed was trying to find the website for Pressure Trace? | |||
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Quote: Yeah, right. NIST doesn't know anything about calibration. You are really an EE. Wheeler is a statistical nobody, and his methods for testing repeatability mean nothing. CDH doesn't really calibrate PSI in terms of mass. How could we be so blind? The whole scientific world, united in error, exposed and brought to shame by Hot Core. | |||
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from DJpaintles, I'm at Lb404's... Hot Core, I'm not going to claim to be anyone's genius. Denton certainly is way beyond my undergraduate level of Higher mathmatics education level. I have been reloading for 29 years and currently reload in the neighborhood of 45 different calibers. I've managed to keep all my fingers and eyes and have yet to blow up a rifle so figure I may have a reasonably sound reloading plan. I've enjoyed the back and forth debate here and hope that no feelings have been hurt........DJ | |||
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Quote: HC, No need to respond if you will not do likewise. Here is a question you asked about the data that you posted: 1. How any of the above Loads "Calibrated" the M43? And here was an answer from denton: 1. None of the loads calibrated the M43. The M43 is calibrated by taking the ID and OD of the chamber at a point about halfway down the casing, where the strain gage is applied, and by applying the standard NIST procedure for indirect calibration. The system is then calibrated within a tolerance. So your question(s) have been answered. You may not like or accept the answer,....... but you can't pretend your questions have not been answered. From your own answers I must conclude that you accept HSGS as valid for relative pressure comparison (ability to compare a reading to a reading from fired factory cartridges). That would make HSGS as useful as a the PRE method. Additionally, I believe HSGS has much more resolution than PRE......possibly by an order of magnitude. Finally, I, and many others, believe that teh Pressure Trace system is accurate to within 1,000 psi of absolute pressure and is calibrated by the method denton has described so well. I still can't see how it's more accurate (or easier) to take PRE measurements to 0.0001" than it is to measure for HSGS to the nearest thousandth of an inch. This is true even if one must take their rifle to a machine shop for an accurate measurement as it only has to be done once while the PRE measurements are done over and over and over and.......... By the way, I think it is you who is making the insane statements trying to get fools (like me) to respond! | |||
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I would invite all interested parties to contact OK Shooter and buy a copy of his 30-06 reloading manual. It is the best reference on the 30-06 but also the issues of pressure and it's evaluation. He is a retired ballistics consultant for the armed services. He knows his stuff. Basically he says you can't accurately determine pressure by the brass. Certainly blown primers or cases means too dang much pressure. How much too much? How much can you reduce that load and make it safe? Sometimes brass looks and measures WNL and is wayyy over the top as far is pressure. M 43 is the best bet. good luck. Don't blow yourself up! | |||
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The Accurate Reloading Forums THE ACCURATE RELOADING.COM FORUMS Guns, Politics, Gunsmithing & Reloading Reloading Re: How do I figure out pressures?
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