@Fireflite - if they follow the original M96 6.5 X 55 Swedish specs, it may be 1:7.5 twist.
My old milsurp M96 had this twist rate - a rifle I should've kept, but being 'young and stupid' at the time (45 years ago), sold it for $100.
Stug could be correct as well, modern powders may prove that a fast twist like this isn't needed, but I'd suggest that anything other than original spec., is a custom barrel.
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