Not claiming to be an expert on this but I think only my oldest AR15 has a 1 in 12 twist rate. I've read that this means that the 55 grain bullets are stabilized but perhaps not the 62 grain that is quite common.
That rifle was built out of surplus M16 parts and in appearance differs little from the rifle I trained with in 1968.
As far as I know just about everything else that is available in .223 has, I think, a twist rate of 1 in 9. You might want to check this out. I picked the .223 because it is such a common round.
I intentionally have (at least) 1 AR that is configured for 1-in-7, to stabilize heavy bullets.