mcb
Member
This was my understanding....and I may very well be wrong. That 44 Mag chamber pressures were lowered by SAAMI(somewhere around 1995)from 43,500 CUP to the current 36,000 psi, which was a realistic 10% reduction, not just a different type of measure. Similar to the change from 46,000 CUP to 35,000 psi in .357. Not only just a change in the way pressure was measured, but also a real reduction in chamber pressure(even more than with .44mag). This had to do with K-Frame S&Ws not holding up well. These changes not only helped the longevity of S&W revolvers, but every other revolver on the market too.....including Ruger. I believe this was something told to me by a retired gunsmith from another forum.
But in either cartridges that change from crusher to transducer does NOT result in a change of actual pressure.
If you have a pressure barrel that was instrumented with both a crusher and transducer measurement system and loaded a 44 Magnum cartridge that produces 40,000 CUP (Crusher) then we would expect a measurement of ~36,000 PSI (transducer) on the transducer system. This relationship is only true for 44 Magnum. Another cartridge would produce a different relationship between the two measurement systems.
For all the examples I gave above if you had a duel sensor pressure barrel and loaded it with a cartridge that produce the max pressure for one measurement system we would expect a measurement very close to the Max value listed for the other system.
I have photo copies of SAAMI specs going back to 1993 for the 357 Magnum and the pressure values did not change. I am still looking for copies of the SAAMI spec that pre-date 1993 but so far no one has shown me consecutive SAAMI publications that have changed the pressure for an established cartridge.
ETA when you mix in Europe's CIP values that use another different way to measure peak pressure and things are a mess unless you really know where the data is coming from and how it was measured.
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