When a thug on TV sneaks up behind his unsuspecting victim, skillfully attaches a silencer to his revolver, and nails him with a few soundless shots, you’re watching pure fiction.
First, no silencer completely eliminates the sound of a gunshot; at best, it partially suppresses the loud crack from the explosion of gases behind the bullet. In Europe silencers are more appropriately called “sound modulators.”
Second, a silencer is ineffective on a revolver, for as the bullet jumps from the cylinder to the barrel in this weapon, the sound escapes out the side.
In the early part of this century, when shooting was a popular sport, the ecologically minded inventor Hiram Percy Maxim disliked all the noise so intensely that he developed both the silencer for firearms and the muffler for automobiles.
By 1934 the United States viewed the silencer as a weapon unto itself; a Treasury act controlled silencers and placed a high tax on them. Today each state has its own laws; silencers are illegal in New York, for example, but permitted in Connecticut and Massachusetts.
A silencer functions on the same principle as a car muffler. When placed at the end of the barrel of a firearm, the silencer absorbs heat and pressure from the explosion. Spiral veins of steel or bronze wool inside the tube of the silencer actually catch gases behind the bullet.
As the gases rotate along this longer spiral path, they are broken down, cooled somewhat, and emitted more slowly; the explosion of gases is thereby suppressed and the sound modified.
Silencers vary in size, depending on the model of gun for which they are required, but they tend to be larger than those you see on TV: 2 to 3 inches in diameter and 9 to 15 inches long for a .38 or .357; 1 inch in diameter and 6 to 8 inches long for a .22 handgun or automatic.
Silencers may be hard to come by, but quiet murders are not. By simply wrapping the nozzle of an automatic pistol in a pillow, a gunman can achieve a cheap and very effective means of muffling the sound.