"So I loaded 5 with the new seating depth, OCW powder weight and mixed brass, 3 W-W (lighter) and R-P (heavier). Result was about a 1 inch group at 200 yds. Velocities, as expected, were higher w/R-P brass but those shots did not excessively influence the group size."
That's pretty much it. [img]/ubbthreads/images/graemlins/smile.gif[/img] It sound like you found the OCW, and you found it by searching near the top of Hodgdon's powder charge range. That generally works--and believe it or not, many of Hodgdon's maximums turn out to be OCW load... I don't know why this is, but it seems to be the case more often than not.
I did an OCW "acid test" using some various brass cases for the .243 win. (It's important to note that I had worked up to the particular powder charge with each
of the brass cases prior to this test). Here are those results...
I've also shot sub MOA at 300 yards with the 57.5 grain charge of IMR 4350 behind Sierra's 165 grain Gameking in a 30-06--using five different brass cases and/or primers.
A good load will allow moderate pressure changes and it will still perform well.
Thanks for the post Roy. [img]/ubbthreads/images/graemlins/smile.gif[/img]