Mine is a new Superlight extractor barrel barrel, 1 in 9 twist. I know It would probably enjoy a heavier bullet, but I've been loading the same 52 gr. Hornady HPBT that I use in my 1 in 14 .22-250 because I have lots of them. Both rifles spit them out where they belong, so I guess I'll stick with it for a while. I don't hunt deer with either rifle, so I really have no need for a heavier bullet. When I want heavier, I choose another rifle. After the .22-250, the .243, 7mm-08, .308, .356, .38-55, .45-70...like that. They're all sighted in with the best bullet and load that I've found for that rifle and I don't change anything....most of all, not barrels.....I change rifles.
Pete