None to speak of, just that I've had some 12 twist custom barrels that just shot so incredibly well in that range of bullet weight that it seemed to be a great match. It is said it's no big deal to have an over stabilized bullet, but also that you may gain some velocity with a more suitable slower twist... For me there's no question in a 308 Win/30-06 sized chambering where I'm not going to shoot 200gr bullets...If given the choice I'll use a 1-12. That said if my barrelmaker had a 1-10 on hand and I would have a wait on the 1-12 I'd probably spin on the 1-10.
