I just got a new Ultra .223 varmint 2 days ago and it's a 1:12 twist.
I took a cleaning rod started it about an inch down, I then marked the rod at 9" and at 12". With the marks facing me I just inserted the rod letting the rifling turn it, when the rod had made a full turn, it was the 12" mark I was looking at. So I figure that it's a 1:12 twist.
I was hoping for a 1:9 so I could use some 68 grains. It's ok though, I have a RRA varmint 20" stainless with a 1:8 twist, which will be my varmint/predator rifle and this new Ultra will be my varmint rifle.