Wet vs. Dry Suppressors: What’s the Difference?
Wet Suppressors: More Effective or Unnecessary?
Hollywood likes to make silencers sound really silent. Anyone who has ever worked in real-world conditions knows that a silencer actually suppresses sound rather than silencing it. That’s why many prefer the term “suppressor.” A good can takes the bite off the sound of a bullet’s report. But there is a trick—available to everyone—to make a silencer even quieter: wet suppressors.
What Does it Mean to Run a Suppressor “Wet”?
When we say wet suppressors, we’re not talking about dunking them in water between shots. What makes them wet is what goes on the inside.
When you pull the trigger, the bullet and its gases rip down the barrel, into the suppressor, where the baffles begin redirecting energy and sound waves. If you add a liquid into those baffles (hence the term wet), those gases and sound waves have something extra to pass through, and that results in a reduction in both heat and noise.
Running a suppressor dry simply means shooting it normally, with nothing added. This is the standard and how all noise ratings are reported by manufacturers.
The Science of How Wet Suppressors Work
Any serious discussion of a wet suppressor will include the term ablation. A quick google search will spin you down a grammar rabbit hole. Avoid it. Ablation, in the scientific sense, is a big word for removing part of something. If you were to find a dozen donuts, and eat two, you would be the ablative.
For suppressors, an ablative removes more of the noise of gunfire, but we have to get a bit technical to understand why.
The noise we hear comes from the kinetic energy of a gunshot. A suppressor absorbs some of that energy in the form of heat. It also controls and redirects the expanding gases. Inside of a silencer, there are lots of surfaces that heat up fast. As most baffles are somewhat thin, they cool down quickly, too, by transferring that absorbed heat back into the air.
A wet suppressor allows for more rapid cooling of the expanding gases. There’s more medium inside the suppressor to suck up the heat. And there’s a bit more mass to obstruct the sound waves, too.
The super-heated expansion of the air itself and its subsequent collapse is what creates the boom. Shooting wet adds more for the bullet and expanding air to pass through, dampening—if you’ll pardon the pun—the sound. All of the liquid inside the suppressor would be moving around violently as the bullet passes through, picking up heat and further interrupting the path of sound waves.
Are Wet Suppressors Quieter than Suppressors without Ablative?
Wet suppressors are quieter. That much is easy to hear. Just how much noise reduction you will hear depends on numerous factors. Consider the length and internal volume of the silencer. And then consider how much ablative you might add. The final variable would be the speed of the bullet itself.
Expect something between a 5 dB reduction on the low end, with some combinations producing up to a 10dB reduction on the high end. Subsonic rounds are the best, as a wet suppressor can knock back the muzzle blast and they won’t have the crack that comes from breaking the sound barrier.
10 dB may seem negligible, but it sounds much more impressive. A gunshot that registers in the 130 dB range would sound twice as loud—or more, as one that registers at 120 dB.
What are the Popular Options for Ablative?
If it pours (or squirts), I’d be willing to bet someone has put it in a suppressor. But there are two options that are more popular than others.
The first is water. Water fans point to three distinct benefits: 1. It is free. 2. It is easy to find. 3. It cleans up itself. While water is hardly viscous, it is effective enough.
There are a couple of negatives, though. One is that water runs out if you point the muzzle toward the ground. Water may also weep out of seams. Suppressors are rarely designed to be watertight (though they often are as a result of their tight tolerances). But as the metal heats up, the water has more room to move.
And as that metal heats up, the water does too. It will boil and evaporate. There’s no residue left behind and there’s nothing (extra) to clean up.
Another popular option is wire-pulling-gel. For those who want something with more viscosity, wire-pulling gel is the ablative of choice. It’s designed for greasing up electrical wires that you’re pulling through rough-drilled holes in walls and is available in huge quantities at most home improvement stores.
Anything that is a gel will stay in the suppressor as you move. Once it heats up, it will liquefy more, but this is a great option for those who want to pre-load a silencer at home or those who are hunting and need to move around with their can before they take their first shots.
Either way, adding an ablative is temporary. Some gels leave behind a bit of residue. Some—like hair gels—can get a bit sticky. Additive in gels can also smoke while burning off.
Speaking of burning, we’d recommend against anything that is flammable. Alcohol-based gels, like hand sanitizers, seem like an especially dubious choice.
How to Make a Suppressor “Wet”
This question is going to stir some controversy. Everyone has their preferred method and some of them come with an inherent risk factor that has to be considered.
First of all, don’t point the gun at yourself or anything you don’t want to destroy. And don’t pour water down the muzzle end without considering where that water is going. You also should avoid filling the barrel of the gun with water.
Second, if you are refilling water or gel, avoid burns. Silencers get hot, which is why we often recommend using a silencer cover. That may be why you need to add more water. But be careful.
Third, don’t over-fill. Follow the manufacturer’s guidelines during this step. The air inside a suppressor (or a barrel) expands and moves freely but liquids don’t. Start small and keep the liquids you add from blocking the path of the bullet.
Those who preload with wire-gel sometimes take apart their cans and add gel into the baffles, spreading it out evenly. This is a great option for real-world applications like hunting or field use.
Applying gel to a silencer on a gun is a bit more complicated. If you must, I’d suggest inserting a syringe. The syringe works well for water, too.
You can also pour water into the backside of a silencer and screw it into place—while holding the silencer level. If you are experimenting, or on the range, keep a water bottle handy. You’ll need to do it many times during an average range trip.
If you are new to this, water is a good way to start. Pour some in. Shake it around before you shoot (some swear ice-water is the way to go). We are talking about a medium that sucks up heat, so starting with something that’s cold makes sense. I’ve not seen a noticeable reduction in dB from ice-water (or at least not enough to justify the hassle of keeping ice-water with me on the range).
Should You Run Your Suppressor Wet?
Should you run your suppressor wet? That’s up to you. If you’ve never tried it, I’d highly suggest that you do. On a subsonic .45, or a rimfire suppressor, that extra noise reduction is amazing.
There is one drawback. Semiautomatic guns produce blowback. Even without a wet suppressor, you may notice a bit more gas in your face when using a silencer. We wear eye protection and accept this as part of the package. A bit more blowback is well worth the reduction in noise.
A wet suppressor may have a wet blowback. Water, mixed with some of the burnt powder, will likely spray back. This is what it is and can be messy. The gel inside a suppressor is less mobile but still can produce blowback.
If you really want to hear the potential of wet suppression, try it on a bolt-action rifle. With a closed system, you won’t get the blowback, for one. A bolt-action .22 with subsonic ammo and a wet suppressor is amazing. You’ll hear more from the impact of the round on the target than you will from the gun.
Other than blowback, I can’t think of a reason not to run wet. Generally speaking, it won’t damage your silencer. I’ve heard some arguments about the water (mostly when refilling on the range) changing the temper on various metal parts. Super-heated metals that are rapidly cooled become brittle, yes—but they’re instantly tempered by the addition of more heat. Any brittleness in a suppressor would be mitigated as soon as you shoot again and heat it back up. This is hardly a concern.
If you haven’t tried shooting a suppressor wet, I’d add it to your to-do list. Put it to the test. Wear your eye protection. See what you think. Is the noise reduction worth the extra effort?