Noise Suppression

Behind the famous “silencer” used in most movies.

Skip Walters

The Professional
Léon: The Professional (1994)
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Movies often have their villain using a suppressor (often called a silencer) to quiet down the guns they use to commit their crimes. As a result, the uninformed public believes the “silencer” allows a gun to be fired with barely any sound. Nothing could be further from the truth.

 

The sound made by the firing of a bullet is similar to the sound made by lightning and the subsequent thunder clap. The lightning creates a vacuum and the sonic boom made the atmosphere rapidly closing that vacuum creates the thunder. Likewise, the explosion of the chemical propellant creates supersonic gasses and a speeding projectile that create atmospheric vacuums that rapidly close, creating a vacuum. As with the lightning, the atmosphere closes the vacuum and creates the report.

 

To decrease the report, the closing speed of the atmospheric vacuum (sonic boom) must be decreased. This can only be done my slowing down the vacuum created by the projectile. The chemical propellant vacuum cannot be decreased in the firing chamber. This is why standard revolvers (with a cylinder gap between the mouth of the chamber and the barrel cone where gas escapes) can never be silenced.

 

The only option is to reduce the sonic boom made by the projectile by slowing its speed and reducing the atmospheric vacuum created or slowing the atmospheric vacuum closure. This is done with a muzzle device that contains baffles to slow the vacuum closure and gently close the vacuum, reducing the report. Coupled with a low velocity projectile, it is possible to reduce a gunshot to less than 100 decibels. A level that is hardly silent, but less likely to cause hearing damage.

 

Europeans use suppressors for hunting and target shooting, to reduce noise pollution. Unfortunately, we, in the US, have allowed Hollywood to create a negative stigma around suppressors. This stigma has been perpetuated by the media. The uninformed fear what they do not understand. Now, you are informed.