Gun Silencers 101

Guns can offer great capabilities to preppers, but there will be times you don’t want to let everyone in the county know you have one when you decide to touch off a round. Maybe discretion is the better part of valor.

Perhaps you don’t want to spook all the animals or set some roving marauders after your trail. It could simply be you want to save your precious hearing and situational awareness when conventional ear-pro is disadvantageous.

No matter what you circumstances and no matter what kind of gun you have, chances are you’ll always be better off with a silencer on your chosen blaster.

The benefits extend beyond a simple reduction of noise at the muzzle, and even better, the times are ripe for you to get one, with comparatively simple paperwork needed to get one in most states and jurisdictions.

In today’s article, we’ll examine how silencers work, the intricacies of mounting one on your firearm, how to acquire one and all of the benefits of sound suppression in a real-life SHTF scenario.

Terminology

Okay, first and foremost, let’s get this straight. Some people will crack down on you over the word “silencer.” They’ll come at you with arguments like, “They are suppressors, not silencers! They suppress the sound of the weapon being fired. They do NOT silence it except for Hollywood movies!”

Check this out, though: The guy that invented them, Hiram P. Maxim, the son of the inventor of a little gun you might have heard of called the Maxim machinegun, called them silencers, so that’s that. In seriousness, either is correct; some folks call them silencers, others call them suppressors.

Those wacky Brits call them “moderators” which is the most English term for it possible. Colloquially you’ll hear gunslingers and wannabe gunslingers call them “cans” ‘cause they look like big cans!

Ultimately, you can use whichever term you prefer, and don’t let anyone else browbeat you with the other. I will use silencer as a rule since it rolls off the tongue a little nicer.

How Does a Silencer Work?

Your silencer, properly designed and attached to your host firearm (more on that in a few) reduces the noise of a gunshot by countering one of the primary factors contributing to its report: the blast of hot gasses issuing from the muzzle behind the bullet when it is fired.

The other major factor is the bullet breaking the sound barrier with a big crack. A silencer does nothing for that, except rare ones which slow the bullet down below the speed of sound before it leaves the barrel.

A suppressor works by capturing the hot gasses expelled from the firearm into a chamber that is filled with baffles. Each baffle within the body, or housing of the suppressor, creates a small chamber that captures part of the expanding gasses.

In this manner, by the time the projectile leaves the suppressor, there are virtually no gasses left to escape and therefore no loud bang. With greater volume inside the housing tube of the device, the expanding hot gasses have more area to dissipate in, thereby trapping more of them inside the tube.

suppressor
This simple diagram shows the basics of a silencer’s internals. Baffles slow, redirect and allow gasses to expand before reaching atmosphere.

This is why a suppressor for a little .22 is about as big as a paper towel roll, and a suppressor for a .50 BMG is three feet long and 2 or 3 inches in diameter. More area, more trapped gasses, and a .50 BMG expels a LOT of gasses.

But at any rate, it is the first and major cause of gunshot noise, the blast, which results in that painful and window-shaking boom when a gun is fired. Any silencer, no matter its design, works very much like a muffler on a car by containing those gasses, redirecting, slowing and cooling them before allowing them to exit the chamber of the silencer into the open air, greatly dampening or even eliminating that boom.

Now, lots of variables are at play in this equation, including the quality and performance of the suppressor, but also the eccentricities of the host gun and even the ammo itself.

What this means is that a great many things have to go just right to get a gun and ammo combo down to what is affectionately known as “Hollywood Quiet”; many guns are still pretty loud, uncomfortably or even painfully so even with a can attached.

Frankly much of the time with most guns firing ammo worth using for self-defense it will be impossible without gravely affecting reliability or performance. But, if there is a will, there is a way: it can be done!

suppressor 2
Modernized internal baffles can take on many unique and eccentric shapes in order to provide as much reduction to noise as possible within a give internal volume.

Just How Loud Are We Talking, Here?

The “loudness” level of sound is rated in decibels, abbreviated dB. A quiet sound has low decibel levels, and a loud sound has high decibel levels. Note that decibel levels increase logarithmically, meaning a sound that appears only twice as loud is actually far louder than that.

A whisper, or rasp of a fingernail over skin, might measure only 15 decibels or so. That’s really quiet, but consider that near dead-silence is 0 dB.

A sound level of only 10 decibels is 10 times louder than that, but a sound level of 20 decibels is actually 100 times louder than 0 decibels! 30 dB is a shocking 1,000 times louder than 0 dB. See how radically that loudness increases?

Let’s talk about really loud stuff. A running lawnmower or small engine is 90 dB. A train horn as we know, is very loud at 110 dB, and that’s at 100 feet! .A jet engine at takeoff power is around 120 dB, which is earsplitting.

On to our favorite noisy tools, guns, your average gunshot is a head-banging 140 dB! For your reference, any sound over 85 to 90 dB causes ear damage over time, and anything at or around gunshot levels of noise is instantly damaging. Them’s the brakes.

A silencer’s effectiveness is measured in reduction in decibels. Now consider that plenty of silenced firearms will only dampen the noise of the shot down to around 100-110 dB, and you can obviously understand from the explanation above that they are still quite loud, even damaging to the ear.

But understanding what we learned about decibels as a measure of power and you will also know that even that “small” drop on the scale is a whopping reduction in noise at the muzzle when you fire.

What About this Supersonic Crack?

The crack that results from high-velocity bullets breaking the sound-barrier is known as supersonic signature, and is very literally a tiny sonic boom! For such a small one though they are quite loud and contribute significantly to a firearm’s noise upon discharge.

This sonic boom follows in the wake of the bullet and is also why you can sometimes seem to perceive two “bangs” at a distance when someone fires a gun far away.

A silencer could be 100% efficient in dealing with the muzzle blast of such a fired round and still be noisy as heck thanks to that sonic boom.

The only way to eliminate this tiny phenomenon is by choosing ammo that is subsonic, or slower than the speed of sound by design or inherently, or by slowing down a normally supersonic round by way of bleeding off those propellant gasses while it is still in the barrel.

This is the province of specially designed integrally suppressed guns, one famous example being the MP5 SD family.

suppressor 3
Integral silencers are essentially a barrel and suppressor built together as one component.

But since many rounds, most rifle and many handgun cartridges among them, are inherently supersonic and depend on velocity for good and reliable performance, you’ll be giving up much of their performance trying to make them as quiet as possible. Oftentimes the tradeoff of reliability for quietness is not worth it and you’d be better off picking a quieter round instead.

Just one more thing to think of if you are trying to get vewwy, vewwy quiet… You know, for hunting wabbits…

Factors for Silencer Use

Silencers are great for nearly every kind of shooting scenario you might find yourself in, from hunting on pristine land to high-volume training that will be heard on your ears no matter how well bagged they are.

Of course, unless you are an infantryman or maybe a cop, in a defensive situation you won’t be wearing any earplugs or earmuffs, but that’s just how it’s going to be. If you have to shoot, you’ll be deafer, but at least you’ll still be alive. I know from experience that the difference between firing a gun outside, and firing one in the confines of an enclosed space, like your living room or an indoor gun range, are huge.

Enter the silencer. The silencer will either attach to the muzzle of a firearm by way of screwing directly on to exposed threads machined into or near the muzzle, called direct mounting, or snapping, shackling, clipping or clamping on to a proprietary mount that is part of the flash hider or muzzle break, often called quick-attachment.

A silencer can also be integral, or made as part of, the barrel, and is permanently onboard so long as the barrel is installed. An integral suppressor is like the entire barrel is inside the suppressor tube itself, or rather the barrel is surrounded by it.

The purpose of the suppressor is to lower the decibel level of a firearm, and to lessen the muzzle blast (the fireball that comes out of the front of the barrel by burning gasses).

Note that the sheer variety of silencer styles, makes, models and attachment methods means there is no plug and play option. You’ll need to understand the intricacies of your firearm and options for mounting a silencer to it against what you need your silencer to do in order to choose the right model.

Luckily this is all easily accomplished by a quick call to a suppressor manufacturer or a gun shop that specializes in them.

Fight the Noise! – Perks of Going Quiet

On the kinder side, using a silencer will ensure your friends and partners around you when you are shooting, at a training class or just on the practice range. In a real defensive situation, one happening during a SHTF crisis or not, a silencer will definitely help save you hearing for future use, especially if you only fire a handful of rounds.

If working on a problem in a group setting, this will make for much easier communication with teammates and identification of fire; if you and all your buddies are running guns with cans, you’ll know real quick who’s shooting at who if someone touches off unsuppressed rounds.

A human, or animal for that matter, who is on the receiving end of suppressed gunfire can be easily confused by the conflicting report of noise; the blast, if your gun creates one at all with a silencer attached, will seem even further away and harder to hear in the first place.

The bullet passing by the target, if supersonic, leaves the sonic boom in its wake, meaning the crack will be perceived as it passes the target, giving the impression of a false source for the shot to the uninitiated.

While that piece of trivia may be more relevant to professionals that preppers, it is not too hard to imagine a circumstance where you’d do well to engage hostiles after TEOTWAKI in such a way as to bamboozle them.
Aside from the cost of the device, and mildly odious regulations needed to get one, you give up only a little in length, weight and bulk to equip your host firearm with one.

Silencers make one of the best arguments for short barreled long guns, since a shorter barrel will offset the added length of silencer and leave your host gun of manageable overall length. Popping a silencer onto the end of a 16” barreled carbine makes for a long and unwieldy package!

Is My Gun Silencer Ready?

Almost any gun, handgun or long gun, can be made to accept a silencer. Some are easier to adapt than others, but luckily if you are a new gun buyer or persistent upgrader you’ll be happy to know that a majority of modern semi-auto and bolt-actions come increasingly “suppressor ready” from the factory. All you’ll need to do is figure out what your attachment system is and which silencer is best for your gun.

If your gun requires modification to accept a silencer, this will require a replacement, suppressor-ready barrel, machining the existing barrel to accept a silencer or its mount directly or the addition to the barrel of a QD mount.

Do keep in mind: some gun and cartridge combos are better than others. The only type of action that will not accept a silencer, or rather gains no benefit from a silencer, is a revolver.

This is because the gap between the face of the cylinder and the forcing cone allows a big blast to escape from their in addition to the muzzle. This spoils any possible benefit of adding a silencer to the muzzle!

There are a few oddball exceptions to that rule, but you don’t really want any of them for prepping, I promise.

Cartridge Quirks and Perks

You’ll be happy adding a silencer to any gun and cartridge combo, or at least happier, but if you want something supremely quiet, or even the vaunted “Hollywood Silent” you’ll need to choose from a fairly thin herd of combinations. Some pertinent details on various common rounds can be found below.

Rifle Rounds

5.56x45mm/.223 Rem. & 5.45x39mm – All inherently supersonic and crazy-fast rounds. Notable that velocity is a must for them to work well against flesh or material.

opping a can on any of these guns will go a long way toward easing the burden of shooting these indoors or out and walking away with your eardrums intact, but trying to go real quiet in a semi-auto through use of subsonic loads will more often than not screw-up what was once a reliably running rifle.

Subsonics are an option in bolt- and other manually-operated guns, but performance sucks.

7.62x51mm NATO / .308 Win. – Another common and sound-barrier busting rifle cartridge. All the same hudles in semi-auto apply here as with 5.56mm above. Bolt-action is easier to deal with and subsonic loads work better owing to greater mass of projectiles.

.300 AAC Blackout – The premier subsonic rifle cartridge. When fired from a silenced rifle, can go from whisper quiet with a subsonic round to AK-like performance with a supersonic round just by switching loads. A niche cartridge, but ideal for those who want AR-handling and a compact package along with reliable performance.

Handgun Rounds

9mm Luger – The majority of 9mm loads today are supersonic, but it is not too tough to find specialty subsonic loads, though a gun and silencer combo may require tuning to make them run with reliable consistency.

Almost every modern semi-auto handgun can be equipped with a silencer of one kind or another.

.40 S&W – No longer the darling of law enforcement, the .40 is still a trusty standby for self-defense. Lighter projectiles under 160-165 grains are almost always supersonic, while the majority of chubby 180 gr. loads are subsonic.

.45 ACP – If you want to go quiet, reaallllyy with your handguns, the old .45 warhorse is still the champ. Most standard loads for the .45 are inherently subsonic, and works like a charm in handguns, subguns, and PCC’s alike for seriously sneaky work.

.22 LR – Supersonic, but you can easily find special subsonic loads in varying degrees. Easy to silence, but again can be tricky to get Hollywood quiet with a semi-auto using subsonics. A bolt-action or semi-auto with a locking breech is disturbingly quiet when fired with subsonic loads.

Buying a Silencer

Once upon a time, you could buy a silencer/suppressor just like you could a firearm. Just order it in a magazine and have it sent to your house. Those days are gone, baby, gone.

Now, you usually have to buy a firearm through a federally licensed firearms dealer. Although, many states do allow face to face sales of firearms so that one person is able to sell a used firearm to another person without any paperwork. This is perfectly legal. Silencers/suppressors are a different story.

These devices fall under the National Firearms Act of 1934, usually just called the NFA. This means that in order to purchase or possess one, you have to obtain permission from the ranking law enforcement official in your jurisdiction, go through a rigorous background check, wait months and months, and then pay a $200 tax to obtain a tax stamp for each device in order to possess it.

Here’s a video showing a Maglite “solvent trap” being used against its intended purpose:

Firearms Trust

Another way to legally posses a silencer/suppressor is through a firearms trust. This is often a little easier to get through the paperwork once the trust has been established, but you need to hire an attorney to get it done correctly.

A little back information is needed here. When an individual purchases a silencer, they are the only person who may possess it. When they die they can’t pass the device or silenced firearm down to a family member because they have to be alive to sign transfer papers, so the government seizes the weapon or device. Expensive family heirlooms are lost.

A trust on the other hand, names several people, usually family members that may possess the device or weapon. So if a family member dies, the remaining trust members maintain possession of the device or firearm.

Since machine guns can cost tens of thousands of dollars, and silencers cost hundreds or thousands, this is good news for surviving family or trust members. You don’t have to be family to be in a trust!

Remember that the easiest and most painless way to navigate this process is through consultation with a shop fluent on accomplishing these transfers or with a silencer manufacturer.

A Quiet, Final Word

So, there you have it. A suppressor can be a fun toy to play with, or it can be an invaluable piece of gear in a combat zone or for self-defense in a grim situation.

Go about it the right way, and purchase a suppressor legally so you will have one ready to go when things get serious and you need to keep your shooting your business. If there ever come a SHTF scenario and laws no longer matter,you can bet your bottom dollar my shots will be silent.

updated 10/17/2019

About Eric W. Eichenberger

Eric W. Eichenberger
Eric Eichenberger is an avid outdoorsman, skilled marksman, and former certified range officer and instructor with nearly 40 years experience handling and repairing firearms. A skilled craftsman with a strong love for working with his hands, Eric spent 20 years as a carpenter and custom woodworker in high end homes. As a gold and silversmith he has created hundreds of pieces of jewelry over the years using the lost wax casting method. The grandson of humble country folk, he was raised with the “do it yourself” mentality and so is accustomed to coming up with unique solutions to problems utilizing materials at hand.

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