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Old 09-06-2013, 18:45   #1
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Join Date: Sep 2008
Location: MO
Posts: 3,088
How to educated guess pressure?

Got back from the range awhile ago. Trying to figure out a load I like using aa2230. Its coming from a colt 6920 16inch barrel 1-7 twist. My load is 62gr ss109 using lc cases at a 2.225 oal, and cci 41 primer.

With 24.4 gr of powder. From my pro chrono, I got 2886 fps on the high end, and 2855 on the low end. Hornadays manual says 24.0 is the max, my lyman manual says something like 26.1 is the max. I did not notice any pressure signs, but is there any way to get an educated guess, or even exact result as to what kind of pressure this is producing? A mathematical formula or something?

I tried everything from 22.0 up to 24.4 same everything except the powder charge. And to get a similar velocity to what I'd like and best results with accuracy the 24.4 seemed to work best. But now it has me wondering if my pressure levals are still safe.
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