I would just ask the Bartlein folks what they recommend. Me I would not go tight bore as it can play tricks with pressure with harder hunting bullets. I like the 5R rifling. Some 308 target rifles are done at 1-11 but for a hunting rifle err on the fast side 1-10 or 1-9. Chrome moly is not as much of an issue as it used to be with Melonite or Ultra Bore Coat for corrosion protection. I believe stainless will hold up longer in regards to throat erosion and it used to be that stainless was more uniform than Chrome moly but that may not be a concern anymore. My main issue would be weight and balance. Even though I'm not a fan I would consider fluting the barrel to improve the balance. If I really wanted to get OCD I would do a gain twist starting at 1-11 and ending up at 1-9 or 9.5. Your rifle order what you want.

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