The Real Scoop on Sound Suppression

Thanks to Hollywood, gun mufflers, sound suppressors or “silencers” — one and the same — are viewed in a negative context by many non-shooters. But the truth is that noise suppressors are used daily—as they have been for more than a century — to enhance safety, ease instruction and improve accuracy for shooters of all demographics.

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To put the function of a sound suppressor it in its simplest terms, the suppressor works by slowing, redirecting and cooling the hot gasses created when the cartridge is fired. We can get into all kinds of scientific terminology, but that is the general function. If we relate it to something we are all familiar with, it will be easier to understand. Think of a balloon. If you release the gas very fast by use of a pin, it will make a “boom.” If you untie the knot and let go, the high-pressure gas inside will bleed out a little slower through the sputtering neck, making much less noise. If you hold the end when untied and slowly let the air out by using pressure of your fingers to control the flow, it will make very little noise, if any. A modern suppressor would fit roughly between the last two examples.

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To get an idea of how well a quality suppressor works, you can compare it to an automobile muffler. If you hear a dragster or stock car running on open headers with no muffler of any kind it will be very loud. It may damage your long-term hearing. That is the case with many unsuppressed firearms. If you listen to an automobile with a proper exhaust system, it will not be “silent” but will certainly not hurt your ears. That is a reasonable general comparison.

Another factor in firearm noise is that many projectiles travel at speeds above the speed of sound. The speed of sound is about 1,115 fps (at 32 degrees F at sea level). Elevation and temperature will affect that number. Anything breaking the speed of sound will produce an audible “crack,” and it is unrelated to the expulsion of gasses when related to shooting. Because of this sonic crack, it is unlikely a gunshot could go undetected, even with the best suppressor on the market. Subsonic ammunition can be used to alleviate some of the residual noise, but it is tough to meet the expectations created by the movie industry.

Click here to read the entire article at AmericanRifleman.org.