Once a rarity in American gun collections, firearm suppressors (also referred to as “cans” or somewhat misleadingly as “silencers”), are increasingly popular; in fact, the number of registered suppressors rose from not-quite 800,000 in 2015 to more than 4.8 million in 2025!
With passage of the One Big Beautiful Bill, the $200 excise tax will be gone as of January 1, 2026. (Onerously, one must still register each suppressor.) With the end of this tax, the popularity of this hearing-protection technology is bound to increase.
Still, many gun owners are not familiar with suppressors, so a primer might be welcomed.
We’ll start with how they work. A firearm emits three sounds when fired: the mechanical sound of the action working, the sonic crack of the bullet (if it is fast enough to break the speed of sound) and the muzzle blast caused by hot expanding gas from burning gunpowder. Suppressors work on this last element, reducing muzzle blast by containing, cooling and delaying the release of the gas, much like deflating a balloon slowly instead of popping it.
Suppressors consist of a tube with a series of chambers or baffles inside with a small circular hole through which the bullet passes. They reduce recoil because the escaping gases push the baffles forward, which lessens the backward-directed recoil, making the firearm more controllable and pleasant to shoot.
Ear protection still needs to be worn in most cases, but the risk to your hearing is considerably reduced when using a suppressor. A related benefit is reduced muzzle flash.
It’s important to know that suppressors can change a firearm’s shot placement, cycling and maintenance. Additionally, the added weight at the muzzle makes the gun less maneuverable and not as quick to get on target.
Suppressors affect shot placement in an unpredictable way. Shot group size can increase, decrease or remain unchanged due to the way the barrel vibrates once a suppressor is attached. Point of impact on target may also shift by a few inches, requiring the sights to be adjusted to bring the firearm back to zero.
Suppressors often change the cyclic speed of semi-automatic firearms, decreasing the time it takes to extract, eject and reload another round on gas-operated arms but increasing the time on locked-breech recoil-operated pistols.
Finally, attaching a can necessitates more-frequent cleaning and lubrication of the host firearm as carbon fouling accumulates more rapidly in the action and oil burns off quickly. (Using high-temperature grease instead of standard gun oils may help.)
Choosing the Right Suppressor
Choosing a compatible suppressor starts with matching it to the type of ammunition used. In that regard, suppressors primarily fall into three categories: rimfire, pistol and rifle. (Shotgun suppressors exist in limited numbers on the market and, so far, offer limited effectiveness.) Rimfire cans are designed for the .22 LR cartridge, but some handle .22 WMR (.22 Magnum), .17 HMR and diminutive centerfire rounds like the 5.7 x 28 mm. Pistol cans are made to suppress straight-walled handgun cartridges like 9 mm, .45 ACP and .40 S&W. A rifle suppressor is designed to handle the higher pressure and gas volume generated by centerfire rifle cartridges like the 5.56 NATO often used for AR-15 rifles.
You’ll also need to consult the cartridge ratings given by the manufacturer and to follow them carefully because a rimfire suppressor rated for .22 LR may not be strong enough for .22 Magnum, and a pistol suppressor rated for .40 S&W may not handle 10 mm. A suppressor’s bore size is also a consideration, since one made for the larger-diameter bullet used in the .45 ACP cartridge can be used on a 9 mm firearm, but not vice-versa.
Be sure to also follow barrel-length limitations. Gas pressure and temperature increase the closer you get to the chamber, so a suppressor designed for a 16-inch barrel may not hold up when attached to a 10-inch barrel. Finally, be aware of any firing-frequency limitations. Sustained rapid fire generates heat quickly, which can degrade metallurgical strength. (For such heavy-duty use, suppressors with stainless-steel baffles are a better choice than aluminum or titanium.)
Attachment Equipment
Mounting your suppressor to your firearm involves choosing between two different methods: direct thread and quick detach (QD).
Direct thread means your suppressor screws onto the end of the barrel, while QD means it attaches to a compatible muzzle device which itself attaches to, or is integral with, the muzzle end of the barrel. A muzzle device can also serve as a recoil brake, a flash suppressor or both. Suppressors with QD mounts attach and detach faster than direct-thread models, but they cost more and are prone to “carbon lock,” where accumulated fouling makes removal difficult.
Many semi-automatic centerfire pistols require a suppressor with a Nielsen Device to cycle properly after the added weight and length of the can is attached to the barrel. Though most pistol suppressors come with a Nielsen Device—also called a booster—you’ll need to match your pistol’s muzzle thread to the thread on the device’s piston. Booster pistons are removable, so you can buy several to fit the different barrel threads of pistols within your collection.
There is much more to know about suppressors, but this information should give you a good foundation to start exploring the options for your own needs.
