We have all see a big budget Hollywood action movie in which a character screws a silencer onto the barrel of a handgun, squeezes off a few rounds, and instead of a loud thunderous crack, we hear a sound that is comparable to a feather landing softly on a pillow.
Hollywood would not lie to us would it? I mean, everything that we see in the movies is an accurate description of what takes place in the real world, is it not?
Well, not exactly…
As a general rule of thumb, silencers do not totally silence a firearm. In fact silencer is something of a misnomer. What is commonly referred to as a silencer is typically called a suppressor. The job of a suppressor is actually 2 fold. It works to reduce (note that I said reduce, not eliminate) noise and muzzle flash, both of which are generated by discharging a firearm.
In order to understand how a suppressor works, we must first understand how a firearm works. A firearm contains an action/chamber. The action/chamber is where a round of ammunition is inserted. In order to fire the round, a striking mechanism (often referred to as the hammer) hits the primer on the round of ammunition, which ignites the gun powder, which then cause the powder to ignite, which leads to the powder rapidly expanding, which in turn forces the bullet down and out the barrel (please bear in mind that that is an extremely simplified version of what takes place). Here are 2 short clips that demonstrate this process.
When the firearm is discharged the expanding gas plus the speed of the bullet break the sound barrier, making that familiar crack, which is essentially a mini sonic boom. A suppressor works to quite a firearm by allowing the escaping gases to be diverted inside the suppressor, which allows it to expand and cool decreasing its pressure and velocity as it escapes the barrel, thus decreasing the sound (again this is an extremely simplified version of what is going on).
The caliber of ammunition being fired also has a huge impact on the amount of noise produced from a firearm. Typically, the higher the caliber, the more powder and thus the faster speed of the bullet being fired from the gun. As a general rule of thumb, the larger the caliber, the louder the crack when the gun is discharged. Consequently, not all firearms will sound the same when suppressed. For example/comparison:
.22 lr ammunition
Here is a video of a 22lr handgun fired normally and then from the same gun equipped with a suppressor.
9mm ammunition
Here is a video of 9mm ammo fired normally and then from the same gun equipped with a suppressor.
.45ACP ammunition
Here is a video of 45ACP ammo fired normally and then from the same gun equipped with a suppressor
.223
Here is a video of .223 ammo (which is typically fired from a rifle), and then the same ammo fired from a similar rifle equipped with a suppressor
And then there is this mammer jammer! The bringer of destruction of doom!
.50 caliber (the one on the far right)
Here is the .50 cal fired through the same rifle, both suppressed and unsuppressed
Additionally the type of ammo is important as well. As mentioned above, regular ammo hits the speed of sound and produces that loud crack when the gun is fired. However there is such a thing as sub sonic ammo. Essentially this ammo is loaded differently then regular ammo, and it is not meant to break the sound barrier. Consequently, when sub sonic ammo is fired, you do not hear that familiar crack. Here is regular .22lr ammo shot from a rifle
And here is sub sonic .22lr ammo shot from a rifle
Additionally here is a handgun being fired (with a suppressor attached) with both regular ammo and sub sonic ammo
So if a suppressor does not completely eliminate the sound of a firearm, what is the point? I mean why would you use something to silence gun when it does not completely silence it?
Good question!
Well in Canada (where I am from + currently reside), suppressors are considered prohibited. That means that a civilian cannot own a suppressor without a specialized licence/permit, and in Canada that particular type of licence/permit is all but impossible to acquire. However, the Canadian military owns and utilizes many firearms that are equipped with suppressors. So that is where we will draw our example from.
The best example that I can think of for the use of a suppressor is a sniper in the military. A suppressor will reduce the noise from an otherwise loud sniper rifle, thus making it much harder to determine which direction a shot came from, thus lessening the chance of the sniper’s position being compromised. Additionally, a suppressor will reduce muzzle flash which also lessens the chance that a sniper will be seen, again reducing the chance that a sniper’s position will be compromised.
So what have we learned from all of this?
Silencers do not actually silence firearms…
And as is so often the case…
Things are often not as they are presented in the movies!
This has been the skeptical samurai
Working to serve…
Through the process of inquiry…
The Skeptical Samurai 