What Are Suppressor O-Rings, and How To Install Them
Kat Ainsworth Stevens
Suppressors have more parts than you might realize. You’re probably aware of some suppressor parts, including the metal tubular housing and internal baffles, but did you know there’s more? Specifically, suppressors have o-rings. There’s often some confusion regarding O-rings, so we’re going to explain what they are, how they work, and why they can benefit you.
What are O-Rings?
Generally, the O-ring of a suppressor is designed to help center a piston or seal sections of the suppressor to prevent fouling. Unlike on a car, which typically uses O-rings to keep fluids either in or out, suppressor O-rings are used more for secure placement and to cut down on how much fouling gets into specific parts. Think of the O-ring on your suppressor like an additional, somewhat shape-shifting part designed to make your suppressor perform at optimum levels, and cleaner ones, too.
Is a Suppressor O-ring different from regular O-Ring gaskets?
Suppressor O-rings are both similar and different from what might be considered a regular O-ring gasket. O-rings are regularly used on vehicles and for plumbing to prevent fluid from escaping an area, but with a suppressor, there’s no fluid involved. So while the name of the gaskets is the same, the purpose is different. The specific shape of the O-rings differs as well. Many O-rings for vehicles and plumbing purposes are circular rubber gaskets with a flat profile. Suppressor O-rings are circular and have a rounded profile (the material that forms the circle is rounded, or tubular, not flattened). This is due largely to the difference in function between the two types of O-rings.
What are suppressor O-Rings made of?
The O-rings used for suppressors are made from different materials depending on the manufacturer and quality. Some are made using Viton, a fluoroelastomer that’s commonly used in the aerospace industry thanks to its ability to retain its shape and maintain a good seal when exposed to high temperatures. Others are made from silicone which is preferred by some. Silicone used for O-rings is generally made from silicon atoms and oxygen atoms, making it a more heat resistant, elastomer than some compositions. There are manufacturers who favor silicone for its ability to withstand a wide range of temperatures.
Which is better? Viton has become a bit of a broad descriptor for fluoroelastomer rubbers in general although it’s actually a brand name. It has the benefit of being designed to keep sealed when exposed to a great deal of heat. Viton is resistant to heat and chemical exposure which can translate to a longer life and the ability to stay in place better if and when it comes in contact with gun lubes and oils. As for silicone, it’s certainly a well-known and respected material that’s impressively flame retardant.
What does an O-ring do in a suppressor?
Exactly what a suppressor O-ring does depends on the specific O-ring. Some suppressors have O-rings to hold the caps in place and perform other sealing functions. Speaking broadly, O-rings in suppressors are designed to help keep parts together and sealed rather than allowing them to unscrew or otherwise loosen during use.
If you have a suppressor with a booster, there will be O-rings on the piston that need to be kept clean and lubed. Those are usually placed between the booster housing and piston with the exact number depending on the specific model of suppressor. These O-rings exist to help keep the piston centered and cycling properly during use.
In addition, SilencerCo utilizes a small O-ring on the mounting threads of a rimfire suppressors for the purpose of helping keep your barrel’s threads cleaner due to the general dirtiness of .22LR. Also, the SilencerCo Warlock and Spectre II have O-rings located at the front cap to keep the cap secure. Then there’s the SilencerCo Sparrow, which has two O-rings around its core for the purpose of sealing the halfpipes and to prevent fouling between the core and outer tube.
Finally, be aware that some mounts also have O-rings. One example is the SilencerCo 3-Lug mount, which has an O-ring around the plunger within the housing. The varied locations of these O-rings is a good reason for users to be at least somewhat familiar with the construction and components of their suppressors.
How often should I replace O-Rings?
O-rings on a suppressor last for quite some time, but sometimes they do need to be replaced. O- rings that have dried out, experienced excessive wear, or become warped or malformed should be replaced. Otherwise, it’s not a bad idea to replace the O-ring whenever you clean your suppressor. That way you’re being proactive rather than waiting for something to go wrong.
Now, the O-rings on a pistol suppressor might need more frequent replacement, especially if they’re not kept clean and lubed. Make sure you don’t use solvents on O-rings because that can cause them to break down and fail significantly faster. The frequency with which you need to clean your suppressor, and replace your O-rings, depends heavily on round count and the caliber of the gun (as well as the ammunition you’re using).
Keep in mind that when you’re mounting your suppressor to the barrel of your gun, the
suppressor should be indexed on a machined surface. The majority of suppressors index off a 90 degree shoulder. This means an O-ring should not be placed on the barrel threads themselves, because it interferes with the proper mounting of the suppressor to the barrel.
How do I replace O-Rings in my suppressor?
To replace the O-rings in your suppressor you first must know where they are. The best way to figure this out is consulting your manual or contacting the manufacturer. Possible locations include the front end cap, rear end cap, piston housing, piston, and bore. If they become stuck, they can be carefully removed with the edge of a punch or other narrow tool as long as you’re cautious not to gouge or otherwise damage the metal of the suppressor itself.
Kat Ainsworth Stevens
