Abstract: A prong-type harmonically de-tuned flash suppressor that is usable with a sound suppressor. As a consequence of its harmonic de-tuning, the flash suppressor does not produce an audible ping when the firearm to which it is attached is discharged, due to harmonic variance among the prongs of the flash suppressor. Harmonic variance, or de-tuning, of the flash suppressor is accomplished by varying centers of gravity of the prongs such that each prong of the flash suppressor has a different fundamental harmonic than each other prong. This harmonic de-tuning of the flash suppressor is accomplished while maintaining each prong at an equal length to each other prong, and while maintaining the general exterior appearance of each prong as being about the same as the general exterior appearance of each other prong. Centers of gravities of the prongs, and thus fundamental harmonics of the prongs, may be varied by placing payloads within the prongs which serve as harmonic dampers.