I just bought a Remington 700 sendero sf 2 in 300 win mag. I took it to my.gun Smith. To get it threaded and have a Holland ad brake put on it. The gun Smith said that cause its a factory barrel and how Remington makes thier barrels . Putting a threaded muzzle brake would mess up the harmonics of the barrel and make it inaccurate. Is he right . Need info.