Pac-Nor suggested a 1:9 twist when I was shopping for a .243 Win barrel. It works fine for everything, so far, but I haven't shot long bullets, except for Barnes 85 gr. TSX and Hornady GMX 80 gr. bullets, which are about long as 100 gr Sierra SPBTs (and shoot very well).
“God save us from people who mean well.”
― Vikram Seth