Don't know but they sure look cool. I have heard reports that the shock absorbers in the stock seem to help. I have a Pro Hunter ss pistol barrel in 7mm-08 and the only difference that I can tell is that the barrel is fluted. I'm not sure if there is any more love put into making it than the standard factory barrel. I doubt it, it was only $250, $15 more than the standard. Is there any difference in the frame? I need to get another frame and I guess it will be a pro hunter, why not get one???