I can't even imagine how loud these will be!!!! I had the 16" in 223 and with that brake on it, it almost rang your ears with good hearing protection on! My buddy was behind me with his good ear protection on when I shot it. He had never seen it shot before, and he jumped, it was so loud!
I have a 16" Ruger American Ranch in 7.62x39, and it was the same without any muzzle device on it, almost rang your ears with good hearing protection on. I had to buy an inline compensator to force the sound to go downrange. Works well. They should all come with such a muzzle device!!!! 308 would be rudely loud! There is no reason why they can't put a better muzzle device on them!