Does a compensator add to the velocity of a gun?

"a compensator is a piece fitted to the end of the barrel of a gun. typically its a tube with holes in the top. its purpose is to limit the upward verticle travel of the muzzle when the weapon is fired. the purpose of this is to increase the accuracy of the following shots."

Some times it is fitted to reduce recoil in large cal. weapons like the Barretta M107, with such a large cal. (50 cal.) the recoil can just break your bones.

This type of compensator has T ITS side vents that are tilted backwards to redirect exhaust gases backwards pulling the gun away from shooter therefore balancing forces and keeping an accurate shot and no broken bones :)