Just purchased a Savage fp-sr in 223. It has the 1:9 twist barrel. I am debating between the 69 grain and 77 grain SMK. Any reason to lean one way or another? I have read that the 1:9 twist barrel will stabilize the 77 grain SMK because the bullet has a relatively short bearing surface. I plan to shoot out to 600 yards so I suspect the higher BC on the 77 grain can't hurt anything. Does anyone have personal experience with the 77 grain SMK not stabilizing in a 1:9 savage. Thanks.