Well, they are VERY good about specifying, so if they didn't specify.
I ask because my CZ 527 has a 1-12 twist.
I dont see on Barnes web site where it says the 55 gr tsx needs a specific twist.Perhaps I've missed it.
"*Many different rifling twists are available in this chambering. It�s important to know your rifle�s twist
rate before selecting a bullet.
*To stabilize in flight, 45-grain Banded Spitzers and 53-grain TSX bullets require a 1:12� or faster
twist; 62-grain TSX and 55-grain MPG bullets need a 1:9� or faster twist."
http://www.barnesbullets.com/wp-content/uploads/2008/01/223RemingtonWeb.pdf