I mean I would personally run a Ti Pro 3 on a barrel that size. I just put one on my new 300 Norma project. If it's just a 7 RUM I think the Ti Pro 3 would be more than adequate, even if it is a lightweight build. I don't like having brakes that are too much bigger than the barrel. Even the Ti Pro 1 at .760" OD and 4 ports does a great job making a 300 Nosler that's under 8 lbs scoped a breeze to shoot.
here's the Ti Pro 3 on my 300 Norma. Straight turned to the barrel diameter of .910"
here's the Ti Pro 3 on my 300 Norma. Straight turned to the barrel diameter of .910"