5.56 vs .223 - Again

[zephyp]

Actually, when we refer to pressure regarding cartridges it should be expressed in terms of psi...CUP merely means it was measured using a copper gauge...we sometimes sloppily refer to internal pressure like 50,000 CUP, but I believe the proper representation would actually be 50,000 psi(CUP). The informed might point out that copper gauges have been replaced by more technically advanced doodahs.

Edit: please note that doodah is indeed recognized as a real word and can probably be found in most dictionaries...along with thingamajig and whatchamacallit...

[gunderwood]

Actually, when we refer to pressure regarding cartridges it should be expressed in terms of psi...CUP merely means it was measured using a copper gauge...we sometimes sloppily refer to internal pressure like 50,000 CUP, but I believe the proper representation would actually be 50,000 psi(CUP). The informed might point out that copper gauges have been replaced by more technically advanced doodahs.

Edit: please note that doodah is indeed recognized as a real word and can probably be found in most dictionaries...along with thingamajig and whatchamacallit...

The CUP method was always fuzzy. The conversion from copper crushed to PSI always had lots of error. It has been replaced by piezoelectric sensors which are much more accurate, but very sensitive to calibration errors. Additionally, different specifications put the sensor in different places which yields different results even on the same cartridge. There is a good reason proof pressures are 25% over the max. Lots of error margin.

[zephyp]

Precisely. And in this case doodah is congruent with piezoelectric sensors. Fuzziness and additional error was also introduced by mixing up another standard with CUP which was LUP - lead...the two have been used interchangeably but are not. Hence, some egg headed guy wearing very thick glasses invented the piezoelectric sensor doodad.

Edit: the term doodad refers to a specific doodah. The term doodah is used to generally refer to doodads of an unspecified nature.

[tyler6971]

dont shoot stell ammo.just shoot real BRASS .4.99 ammo is bad for your barrel and other parts.