Thread: Anyone played with 223AI?

Greetings,
As the pressure rises beyond the yield point of the copper cylinder the cylinder starts to deform and continues to do so until the pressure drops so the cylinder is deformed by both the pressure and the duration of that pressure. The cylinder is measuring work or pressure over time rather than pressure. Hence my description of area under the pressure curve. There is not an exact relationship between the work done and the maximum pressure developed as was discovered. Once this was understood the pressure unit was changed from PSI to CUP. The modern system measures pressure directly and pressure is in PSI again but a different one. There are just to many variables to give an exact conversion, the speed of the powder used being just one. As far as the relationship between 60,000 CUP and 70,000 PSI this was general and should have used the word approximately in there somewhere.
Case head hardness varies from cartridge. At one time the hot rod handloaders of the .30-06 worked up their loads in Twin City (I think) brass until the heads expanded and then loaded the same load in Denver brass which was harder and lasted for a few loads more. I hate to think what the pressure was. In those days post WW2 there was little pressure tested data, truly the intrepid years.
Regards Grandpamac.