Southla1. I must beg to differ with you on the 1 in 10 inch twist in .30 caliber. Yes it is the standard, but browning used 1 in 12 inches for years in 30-06, and may even still do so. A 1 in 12 inch twist will stabilize a 220 gr. round nose bullet as far as anyone has any business in doing so.
I have 3 rifles in .30 caliber, one 30-06 and two .308's, all with 1 in 12 inch twists. They will all stabilize the heavy bullets to well past 200 yards, which is further than I'd shoot a round nose bullet anyway.
Time constraints keep me from taking this farther, but E-mail me and I'll give you the details.