A
silencer or
suppressor, is a
firearm accessory designed to reduce the amount of
noise generated by firing the weapon. The silencer is typically a cylindrical piece of machined
metal that attaches to the muzzle of the
pistol or
rifle. It acts as an extension of the barrel, and reduce noise by allowing the rapidly expanding gasses from the detonation of the round, to be trapped inside a series of hollow chambers called baffles. The turbulence from this activity slows the
bullet marginally, but a properly designed and fitted silencer should not noticably interfere with the operation of the
gun at most ranges. The overall effect of a good silencer can be dramatic, up to the point where the only audible noise is the mechanical parts of the gun moving. Silencers are less effective with high velocity rifle
ammunition that breaks the
sound barrier, because the sonic boom left in the bullet's wake is louder than the initial chemical
explosion. Silencers are illegal in America and most developed countries, without extensive licensing.