By far the question we get asked most frequently is what is the quietest suppressor available? No pun intended, but what a loaded question! There are a good amount of attributes to consider when you talk about the quietest suppressor. Things like ammo, barrel length, environment, and even silencer size all play a distinct part. We all want our suppressor-firearm duo to live up to its full potential. So how do we get the quietest suppressed gun? Keep reading for each factor involved, and how to optimize your set up.

Cartridge

The cartridge is the most impactful because it literally determines the amount of boom there is. The explosion that is caused is what makes the noise loud, so a smaller cartridge would mean that it would be quieter.

This is one of the biggest reasons why first time buyers purchase a rimfire silencer first. Not only are rimfire suppressors usually the most economical choice, but it’s also the closest to Hollywood quiet that you’re going to get.  As you get into bigger calibers that offer more powerful options, you’re using more gun powder, meaning it’s ultimately going to be louder. On the flip side, suppressing smaller calibers tends to give you an astoundingly quiet set up.

Caliber to silencer bore ratio: If you think of the combustion that is happening when you fire a round through a suppressed firearm, think about all of that energy needing to go somewhere. If the caliber to bore ratio is small, the firearm might be louder at the ear on a gas operated semi-automatic, due to a tighter tolerance between the projectile and the silencer’s bore, which forces more gas back through the gun. Alternatively, if the bore size is large compared to the projectile shooting through it, there is more opportunity for the gas to follow the bullet out of the end of the firearm, making it louder at the muzzle.

Subsonic vs. supersonic: When describing ammunition, subsonic  is used when the maximum velocity of the projectile of that particular load does not exceed the speed of sound (at sea level) when fired out of that specific barrel length. In layman terms, subsonic ammo operates below the speed of sound.

Alternatively, supersonic means that the projectile exceeds the speed of sound, which in turn creates a sonic “boom” or “crack.” This discernible crack is perceived as a louder noise to the human ear.

In order to eliminate this crack, your bullet cannot pass the sonic barrier, which would then be considered a subsonic round. This is why subsonic ammo is considered the best option for shooting firearms with a suppressor, because it ultimately moves slower than the speed of sound.

Length (and Size)

Barrel Length:This might sound super obvious, but we’re going to say it anyway: the shorter barrel, the louder the sound. So short barrel rifles, for example, will ultimately be louder than their regular-lengthed barrel counterparts because a longer barrel will use up more of the propellant as the bullet travels through the barrel, leading to less “explosion” when it leaves the barrel and enters the atmosphere.

Silencer Size: The similar can be said for silencers. If you’re looking for the quietest suppressor, diameter and length matter! A short or “K” length silencer still provides suppression, but not as much as a full configuration or longer suppressor in that same diameter size. Some suppressors are designed to be shorter, but have a larger diameter to make up for the difference and still provide comparable sound attenuation, like the Omega 9K or the Wolfman, for example.

Action

The type of action will also dictate how loud your silencer is.

Closed Bolt System: These include manual, pump, lever, and bolt actions. Each of these systems will sound effectively the same because of the way these systems run. Closed bolt systems do not rely on the gas of the round to cycle the action, therefore the gas does not have an opportunity to be forced back into the action. So, in these closed bolt actions, all of the gas goes out of the muzzle.

Semi-Auto: These types of firearms have either direct or delayed blowback. Direct blowback forces the bolt open, and are commonly found in 22lr, 380, and 9mm sub guns, and some handguns. Delayed blowback semi-autos have a mechanical device that keeps the bolt closed until the bullet has left the gun. Either way, compared to closed-bolt systems, these semi-auto guns tend to be perceivably louder at the shooter’s ear due to your proximity to the action or ejection port where excess gas is escaping.

Outside Factors

The environment plays a huge factor in how loud a suppressed firearm sounds!

Temperature: We aren’t here to get into the nitty gritty of what sound is doing in varying temperatures in this post, but it’s worth bringing up that it does make an impact.

Surroundings: Sound waves bounce off of any objects around them. So, your surroundings directly impact what you’re hearing. If you’re indoors versus outdoors, or near walls or berms, or you’re out in the open, that will impact what you hear.

Personal: Some people are more sensitive to sound than others, or might hear differently. It’s truly subjective. So a certain tone that sounds good to someone, might sound not as good to another.

Variables

There are variables in each section that we discussed which could lead to a series of rabbit holes and additional blog posts that we could go down and cover. These caveats even involve firearms that exhibit similar gas systems that can provide differing results. Since providing a list of quiet suppressed firearms would be exhaustive, we’d love to hear your quietest suppressor combinations below!

Additional Resources: 

How to Buy a Silencer

Common Silencer Cycling Issues

Reasons to Own a Silencer

Note To The Comments Below

It has become clear to us that the title of this article was misleading and we apologize for the confusion. The intent of this article was to point out that the "quietest" silencer is a difficult thing to define. Different silencers perform differently considering various variables and while one may be great on a bolt-action, it may perform poorly on an AR or AK (and vice versa). There are many considerations to take into account when buying a silencer and we were attempting to point out that quietness is just one. Size, weight, caliber ratings, build materials, attachment methods, price all play a roll. While one silencer may produce meter results that are 1 or 2 db under another, it may be lighter, cheaper, run on more calibers, or have a better mount system for your particular application. Clearly this point was not adequately conveyed and we apologize again for any opposition it may have caused.