Disscussing old, rare, very specific or otherwise uncommon units and measurements
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Postby guest » Sun Sep 09, 2007 11:24 pm

This unit is used in reloading ammunition for hobby shooters it is called cup and stands for Copper Units of Pressure. a small cylinder of copper is placed between a piston and an anvil. when a test shot is fired from a control chamber with the piston in direct contact with the test shot system pressure it crushes this copper cylinder. that is then measured, length wise, and a chart tells the cup used to determin the safety or useabillity of that load. new systems use piezoeletric pressure transducers to convert to good old fashon PSI. is there a conversion for CUP to PSI? because psi is used to tell steel strength and other points of stress or componant failure it means more to me than the older system. on the other hand cup is used in many reloading manuals for powders that are still in use today but go back almoast 100 years. just curious thanks for any help. steve

Postby Dirtman » Tue Sep 11, 2007 11:14 am

Steve, you can get a description here: http://en.wikipedia.org/wiki/Copper_units_of_pressure but I would think tech support at: http://www.sierrabullets.com/ and http://www.hornady.com/ would yield better results IMHO

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Re: C.U.P.

Postby guest » Sat Oct 26, 2013 2:11 pm

US Conversion (ANSI): PSI = -17,902 + 1.516 x CUP
European Conv (CIP): PSI = -2806.88 + 1.20911 x CUP

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