Silencer Guide with Decibel Level Testing
The following is an excellent resource on the effectiveness of suppressors using measured data on a handful of different platforms done by the great folks over at one of our site sponsors, Ammo To Go. Check em out. -NCS
This project is a massive look at silencers with testing data that shows exactly what difference a suppressed firearm can make on your sound levels while shooting.
If you understand how silencers work and would like to jump straight to the data, here is a quick guide to the sections covered in this project:
- How Silencers Work
- Suppressors vs. Silencers
- Benefits of Suppressors
- Are Silencers Legal?
- Silencer Decibel Level Testing
Understanding How Firearm Silencers/Suppressors Work
When you fire ammunition from a gun, the ammo generates hot pressurized gases that need a place to escape.
As these turbulent gases exit the firearm, the dramatic change in pressure causes a loud blasting sound. A silencer’s job is to redirect these heated gases through a system of chambers and baffles to slow down, cool, and limit the pressure and noise emitted from a firearm’s barrel.
Shooting a pistol chambered in .22lr with a Dead Air Mask HD Silencer
One great example of how silencers work can be seen when looking at car’s muffler. A muffler’s job is to take the hot gases and noise generated from an internal combustion engine and slow them down through a system of tubes and baffles. The result comes out as exiting exhaust within an acceptable audio range.
Just like mufflers, there is no one size fits all solution for silencers. They come in different shapes and sizes. This lets us control how loud or quiet we would like our firearm to sound. Firearm silencers are so similar to mufflers because the inventor, Hiram Percy Maxim, actually helped with a lot of the research for improving automobile and industrial silencers. His company, Maxim Silencers, is still running strong over 100 years later and remains a leader in the industrial noise control market.
Suppressor vs. Silencer
Silencers are continually a hot topic of debate between gun owners and gun control advocates. The debate usually starts when asking what exactly we should call these devices.
The term “Silencer” is really a colloquial term for firearm suppressors, and one of the most misleading aspects of the whole debate. Contrary to the term, “silencers” do not completely silence a firearm.
Similar to the whole Magazine vs. Clip argument, there are staunch advocates in favor of never using the term “silencer” when discussing firearm suppressing devices. Many point to the way silencers are portrayed in the media as basis of inaccurate representation of their capabilities.
When used in action films, the bad guys are usually running around gunning down their targets, all while remaining undetected due to the whisper like sound levels of their evil guns. While this makes for a great story telling device, the real-world accuracy of how a silencer actually performs is much different than its Hollywood portrayal.
In reality, most civilian-accessible firearms emit sounds ranging from 140-175 decibels. Silencers only marginally suppress a gun blast, bringing the levels down to around 120-150dB. Most of the time, the sound is still very obviously identifiable as a gun shot.
Many gun owners also fear that inaccurate portrayals could lead to even more regulations for silencers/suppressing devices.
For what it’s worth, the ATF uses the term “Silencer” in their yearly statistical update for sales and applications for firearms and other NFA items.
Oh, and Mr. Maxim, the inventor himself, called them silencers. So, in the suppressor vs. silencer debate we’re going to call them silencers out of respect to Mr. Maxim. But, know we’re not advocating the Hollywood portrayal of these tools as accurate.
How Effective are Silencers?
When it comes to a silencer’s capabilities, there is a short and simple answer to the question, “How much quieter is a gun with a silencer?”; It depends.
There are many factors that go into how a suppressed gunshot will sound. The type of silencer used, firearm/caliber choice, ammunition being fired, even temperatue and atmospheric conditions can all impact the overall sound a firearm emits.
Silencers mainly focus on controlling the sound level emitted from firing a round of ammunition. But keep in mind, a firearm’s action also creates mechanical sounds when cycling rounds of ammunition. These sounds are in no way changed by the use of a silencer.
Caliber and Firearm Choice
Since silencers can be expensive and a hassle to purchase, many people opt for a model that will work well with multiple calibers. One popular choice is using a .30 caliber silencer to shoot rounds such as .308/7.62 NATO, and 300 AAC BLK, but also using it to shoot smaller .223 and 5.56 NATO rounds.
Even though a .30 Cal silencer will suppress a gun shot from a smaller caliber, the sound isn’t as suppressed as it would if the shooter were using a model made exclusively for the round being fired.
Barrel length can also have an effect on the overall sound levels of a gun shot.
Generally, the shorter the firearm barrel, the louder the blast will be. A longer barrel allows more time for the powders and gases to burn before escaping the end of the muzzle.
Subsonic vs Supersonic Ammo
Along with the sound of the action, there is an additional insuppressible noise that comes into play, but it has to do with the actual projectile itself.
Since the use of a silencer does not alter the performance or velocity of the bullet being fired, when the projectile breaks the sound barrier you will hear what’s commonly known as a sonic boom or in this case, a sonic crack. This audible confirmation of a high velocity p