My Colt Hbar II had 1/9 twist, My first RRA had a 1/7 and the last two have 1/9
As I said each of those rifles had/have a favorite match ammo that would produce 1" or better 5 round groups.
It was when they were fed cheap 55gr FMJ ammo that I got 4" groups. Mind you these were typically 20 round groups, fired in one string from the bench. Same scope used on each rifle, a Leopold 3X-9X.
Stopping power: The power some guns have to make you stop what you are doing and get your wallet out.