In the thread on the Winchester M70 vs. the Remington, one poster notes that Winchester has recently gone to a 1-10" twist on their .308's...a move that I like!
Many .308's have a 1-12" rifling twist. 30/06's usually have a 1-10" twist, as they once were often used with 220 grain bullets and a slower twist wouldn't stabilize long bullets as well as a 1-10" twist.
I suspect that a faster rifling twist may impart greater expansion or energy loss in flesh than a barrel with a slower twist. The bullet may well do more damage.
John Jobson, the late camping editor of, "Sports Afield" noted that in shooting groundhogs (and I think, deer), he found his .270 with 1-10" twist more damaging to the target than a .270 with 1-12" twist. And trials of Colt vs. S&W .38 and .357 revolvers show more expansion from Colts, which have a 1-14" twist vs. the 1-18.75-inch twist used by Smith & Wesson. The difference is so marked that in one NRA test, a snub Detective Special produced expansion about on par with a S&W M10 with four-inch barrel, although the longer barrel naturally produced more velocity.
I suspect that relatively fast twists used in foreign 6.5MM and 7mm rifles may have added to their reputations for killing power. (Some US rifles in these calibers may use slower twists, especially in custom barrels.)
Has anyone observed anything to confirm this effect?
Lone Star
Many .308's have a 1-12" rifling twist. 30/06's usually have a 1-10" twist, as they once were often used with 220 grain bullets and a slower twist wouldn't stabilize long bullets as well as a 1-10" twist.
I suspect that a faster rifling twist may impart greater expansion or energy loss in flesh than a barrel with a slower twist. The bullet may well do more damage.
John Jobson, the late camping editor of, "Sports Afield" noted that in shooting groundhogs (and I think, deer), he found his .270 with 1-10" twist more damaging to the target than a .270 with 1-12" twist. And trials of Colt vs. S&W .38 and .357 revolvers show more expansion from Colts, which have a 1-14" twist vs. the 1-18.75-inch twist used by Smith & Wesson. The difference is so marked that in one NRA test, a snub Detective Special produced expansion about on par with a S&W M10 with four-inch barrel, although the longer barrel naturally produced more velocity.
I suspect that relatively fast twists used in foreign 6.5MM and 7mm rifles may have added to their reputations for killing power. (Some US rifles in these calibers may use slower twists, especially in custom barrels.)
Has anyone observed anything to confirm this effect?
Lone Star
