| 400NitroExpress |
| (.400 member) |
| 06/10/06 03:07 PM |
Re: My 450 No.2 build for those who asked
|
In reply to:
"apples and oranges"
Nope. BaseCUP (a measurement of bolt thrust), which was the original British standard, and CUP are apples and oranges, as are BaseCUP and PSI. CUP and PSI are both measurements of the same thing at the same place - chamber pressure on the chamber sidewall - by different yardsticks - copper crusher vs. piezo electric transducer.
In reply to:
"note I said CUP"
Yes, you said CUP, which is part of what is wrong with your statement. With the sole exception of the .470, there are no chamber pressure standards for the Flanged Nitro Expresses stated in CUP, because SAAMI has never standardized them. CIP HAS standardized these cartridges - in PSI. You said the .450 No. 2 had a pressure of 32000 CUP and that "the others" were 40000 to 44000 CUP, which they are not. Since there are no standards in CUP for these cartridges, I used PSI so that an accurate comparison could be made.
In reply to:
"Note the roughly 5000 PSI lower pressure for the .450 #2 and the .450 Nitro?"
Note the roughly 5000 PSI higher pressure of the .450 No. 2 in comparison to the .500/.465 and the .577? Note lower pressures of the .470 and both .475 No. 2s? Note that the .450/.400 and .500 have the same pressure as the .450 No. 2? The .450 Nitro is the only one that produces higher pressure than the .450 No. 2.
Your statement was wrong.
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