240 Wby with a 1/8. I see no advantage to a 6/06.
6-06 gives you multiple options to “make” brass. The 240Wby is an island unto itself for me that’d be reason enough to bail on the 240. A good friend has a NULA in 240 (1:7) it’s an absolute hammer w/110 A-Tips. But, it was a pain in the rump rounding up brass.
Regarding the OP’s original question. If you’re starting from scratch, there’s no way I’d go less than 1:7. Look @ where projectile R&D is going. Nobody is gonna be wishing for slower twists anytime soon.
