TexasCHLforum.com

Unless something has changed, most 6.8 barrells are threaded for the same standard on the muzzle as .308 barrels. On my 6.8 SPC build I am running a YHM 30 cal flash hider. If you look hard enough you can find 6.8 specific muzzle devices, but they use the same threads as the .308 version. There's a good reason that they aren't too popular as the manufactures don't want to risk someone screwing one onto a .30 cal firearm (This would result in much ungoodness).