A convertible ballistic optimizing system includes a main body portion adjustably secured to the muzzle end of a firearm. A retainer, such as a lock nut, is utilized to secure the main body portion in a particular axially position to change vibrational characteristics of the firearm barrel so that the bullet exits the muzzle end of the firearm when the barrel is undergoing the least amount of transverse movement. The main body portion includes a plurality of apertures that function as a muzzle brake when a weight element is attached to the outlet end of the main body portion. Alternatively, in place of the weight, a sleeved end piece can be secured to the outlet end of the main body portion to cover the apertures, thereby disabling the muzzle brake feature, without adversely affecting the inherent accuracy of the firearm.