I talked to Sierra a few years ago about the Pro Hunter, twice. One tech told me that the 150gr is way to hard and will just pencil through at 7.62x39 velocities. Another tech told me that although the Pro Hunter is designed for velocities much higher than the 7.62x39 can produce it will still expand some. I'm not sure what "some" means. I gave up on the Sierra Pro Hunter as a hunting bullet in my Mini-30. The 7.62x39 is handicapped enough already without shooting a bullet that may not perform.