Handloading guides by Lee and Lyman, to this date, use predominantly C.U.P. data, which has not been of much use for working up loads with QuickLoad Ballistic Calculator software.
Here is the link that GunnyMack supplied via an online link to "NFG's" offering at MarlinOwners.com:
http://www.marlinowners.com/forum/reloa ... rmula.html
WARNING! Rough Estimates, Only!
PSI TO CUP
(PSI + 17902)/1.516
CUP TO PSI
-17902+(1.516XCUP)
Math Operation Order:
My Dear Aunt Sally – M D A S
Multiply, Divide THEN Add and Subrtact
Here is one listing from AmmoGuide that had a C.U.P. pressure rating. It was ran through QuickLoad using the same data. As per the warning, at least it gives you a ballpark figure to work with.
CARTRIDGE AND LOAD:
Sierra 170 gr. FP .30-30, H4198 22.5 gr., COAL 2.250" in a 24" barrel
AmmoGuide listing
1918 fps, 32,600 C.U.P. (= 31,520 PSI in conversion formula)
QuickLoad estimate
1981 fps, 31,749 PSI
My Excel application:
We need to be mindful, again, that:
* The conversion formula is an estimate
* QuickLoad data is all an estimate
A simple, bare bones Excel file (offered below) can be altered if you remove the "Protection" on it. It is not locked with a password. The cells are protected so that you only enter data in one of two cells so that the calculation will work.
If you use Excel and want this very simple tool, you can download either version through the following links:
PSI and CUP Converter.xls
(Excel 97-2003)
https://app.box.com/s/pneg62bse31bmh2jz8kaswitho8nmc8f
PSI and CUP Converter.xlsx
(Later versions Excel)
https://app.box.com/s/6tg49h0n6jttcfv3m9dei0dm45y6kpzx
Now the Lyman data, and that of others like Lee's handload book, will be much more useful for me.
Thanks again, GunnyMack.
