How ‘Cans’ Work

posted on October 8, 2015

Suppressors are often referred to as “cans” because they look like, well, a soda can on the end of a barrel. Note that “silencer” is really not the correct term; suppressors don’t actually silence anything. They merely reduce the audible sound emanating from the muzzle of a hunter’s rifle to differing degrees.

Guns make all kinds of noise when we fire them: The firing pin strikes the primer; the action cycles on auto-loaders; and of course there is the big boom—the propellant gases exiting the muzzle and the bullet breaking the speed of sound as it flies downrange. The escaping gases account for most of the boom we hear when firing.

A suppressor offers 20-30 times greater volume compared to a thin rifle barrel. With one in place, the pressurized gases behind the bullet have a much greater space in which to expand, so the pressure of the gases falls significantly. The bullet is not traveling as quickly when it exits the muzzle so noise is lessened. Most suppressors contain escaping gases with a series of small chambers separated by baffles. To do this, manufacturers use different angles, ports and dimensional adjustments to spread out the gases and quiet them. The can above is made by Dead Air Armament.

Gunshots produce noises in the range of 160-180 decibels; a good suppressor will cut that by 20-40. The best suppression coupled with optimum ammo makes the report of a rifle sound like a high-pressure air release. If supersonic ammo is used, the crack of the bullet as it exits the muzzle and breaks the speed of sound still creates a loud noise; shooters are still advised to guard against it by wearing hearing protection. Sub-sonic ammo produces lower decibels, but of course it may not produce muzzle velocity and downrange energy sufficient for killing game, and the bullet still can be heard as it zips through the air. On an auto-loading rifle, sound still escapes via the ejection port. Some suppressors are designed to be used “wet”; that is, the user fills the baffle cavities with water or some manufacturer-specified medium. “Wet” provides more suppression than “dry,” however, “wet use” must be followed to the T or else disastrous effects can be realized.

Most suppressors are made of steel and high-tech alloys, and their seams are welded. The best cans are expensive. Cans meant for .22 rimfires, however, can be made with aluminum and thus are cheaper.

Suppressors come in three categories: integral, thread-on and quick-detachable (QD).

An integral suppressor is built around an existing rifle barrel. Usually, the attachment is permanent. The barrel is often ported in multiple locations along its length, which allows gas to be siphoned off and dampened inside the suppressor. An integral design usually cannot be replaced due to wear without also replacing the barrel, thus this usually results in a firearm used for special purposes only.

Thread-on cans once were commonplace but are gradually being replaced by QD systems. They are simply screwed tight, and so they can be difficult to regulate; minor variations in torque can affect a rifle’s zero. This problem seems greatest with centerfire rifles.

QD cans offer easy-on, easy-off flexibility, and so they are becoming the norm in the market. They provide positive, repeatable indexing when locked to a flash-hider or muzzle brake common on AR-15s, which is critical to reducing an inevitable point-of-impact shift when attaching a can to the end of a barrel. They must be securely locked or else they may very well launch upon firing the first round.


Silencer Central INC 5000 Lead
Silencer Central INC 5000 Lead

Silencer Central Makes Inc. 5000 List of Fastest-Growing Companies

Silcencer Central has made the Inc. 5000 list of fastest-growing private companies in America.

Smith & Wesson Introduces Model 350

Smith & Wesson has introduced the Model 350, the company's first production revolver chambered in the powerful straight-walled 350 Legend.

Members' Best 2022

Be it a bucket list hunt in a land of giants, an anniversary escape with a loved one, a quick scouting trip turned big-buck showdown or the culmination of a trophy slam, American Hunter readers searched for and found opportunity near and far this past year.

First Look: Buck Bourbon Rack House Blind

Veil Camo has announced the integration of its Wideland Camo pattern with the new Buck Bourbon Rack House 300+ One Way Mesh hunting blind.

First Look: Canvas Cutter Dominator 2.0 Bedroll

The Dominator 2.0 Bedroll is Canvas Cutter’s flagship outdoors sleep solution, designed for any backpacking, hunting, fishing, or camping adventure.

Florida Expands Gator-Hunting Hours and Equipment

Gargantuan gators beware! Florida's 2022 hunting season started on Monday, 8/15 with brand new rules regarding hunting hours and acceptable equipment.


Get the best of American Hunter delivered to your inbox.