I need to swap out muzzle devices on a very heavy profile barrel with flutes and taper and my normal aluminum barrel vise blocks I use for AR barrels just weren't going to work. A little internet searching and the Viper Barrel Vise popped up and seemed to be highly liked. I ordered one plus the Inline Fabrications quick mount plate. Both arrived within a week and I'm up and running. This thing is fantastic and I wish I had bought one years ago. Highly recommended!