The Source of Gunshot Noise
When a firearm discharges, three things create noise:
The muzzle blast is the loudest component. Hot, high-pressure gases exit the barrel behind the bullet and expand rapidly into the atmosphere. This sudden expansion creates a powerful sound wave, typically measuring 140 to 175 decibels depending on the cartridge.
The sonic crack occurs when a bullet travels faster than the speed of sound (approximately 1,125 feet per second at sea level). The bullet creates a small sonic boom as it breaks the sound barrier. Supersonic ammunition produces this crack regardless of whether a suppressor is attached.
Mechanical noise comes from the firearm's action cycling. Bolt movement, springs, and metal-on-metal contact all contribute to the overall sound signature.
A suppressor primarily addresses the muzzle blast. It has minimal effect on sonic crack or mechanical noise.
How a Suppressor Reduces Sound
Inside a suppressor, a series of chambers separated by baffles gives expanding gases somewhere to go before they reach the atmosphere.
When the bullet exits the barrel, propellant gases follow close behind at high pressure and temperature. These gases enter the suppressor's first chamber and begin expanding. As they pass through each baffle, they lose energy, cool slightly, and slow down.
By the time the gases exit the suppressor, they have dropped in pressure and temperature. The resulting sound wave is less intense than an unsuppressed discharge.
The concept is identical to an automotive muffler. In fact, the earliest firearm suppressors and car mufflers used the same basic technology.
Decibel Reduction in Practice
Sound is measured in decibels (dB), which use a logarithmic scale. A 10 dB reduction sounds roughly half as loud to human ears.
Most suppressors reduce gunshot noise by 25 to 35 dB. Here is what that means for common calibers:
| Firearm | Unsuppressed | Suppressed | Reduction |
|---|---|---|---|
| .308 rifle | 165-173 dB | 134-148 dB | 25-35 dB |
| 5.56/.223 rifle | 165 dB | 132-140 dB | 25-33 dB |
| 9mm pistol | 160 dB | 125-135 dB | 25-35 dB |
| .45 ACP pistol | 157 dB | 125-132 dB | 25-32 dB |
| .22 LR | 140-153 dB | 110-125 dB | 25-40 dB |
The threshold for hearing damage from a single impulse is around 140 dB. Many suppressed firearms still exceed this level, which is why hearing protection remains advisable for extended shooting sessions.
Suppressors bring noise down to safer levels. They do not create silence.
Suppressor vs. Silencer: What's the Difference?
Nothing. The terms are interchangeable.
"Silencer" is the original term used by inventor Hiram Percy Maxim when he patented the device in 1909. It is also the legal term used in the National Firearms Act.
"Suppressor" became common in the firearms community because it more accurately describes what the device does. It suppresses sound rather than eliminating it.
Both terms refer to the same device. Use whichever you prefer.
Why Subsonic Ammunition Matters
Supersonic ammunition creates a sonic crack that occurs downrange as the bullet travels. A suppressor cannot eliminate this sound because it happens after the bullet leaves the device.
Subsonic ammunition travels below the speed of sound, eliminating the sonic crack entirely. Combined with a suppressor, subsonic loads can be substantially quieter than supersonic ammunition.
The tradeoff is ballistic performance. Subsonic bullets carry less energy and drop more at distance. For applications where maximum quietness matters more than terminal performance, subsonic ammunition makes sense.
For hunting and practical shooting, supersonic ammunition through a suppressor still provides meaningful noise reduction and hearing protection. The sonic crack is less concerning when it occurs well downrange.
Suppressor Construction and Materials
Suppressors are built from various materials, each with tradeoffs:
Aluminum is lightweight and affordable but cannot handle sustained high-volume fire. Rimfire suppressors commonly use aluminum construction.
Stainless steel offers durability and heat resistance at moderate weight. Many pistol and rifle suppressors use stainless steel baffles.
Titanium provides excellent strength-to-weight ratio. Premium rifle suppressors often use titanium to minimize barrel weight.
Inconel and Stellite are specialty alloys that resist extreme heat. These appear in suppressors rated for fully automatic fire or heavy use.
Effect on Accuracy and Point of Impact
Adding a suppressor typically has minimal impact on inherent accuracy. Some shooters report tighter groups with a suppressor because the reduced recoil makes follow-up shots easier.
Point of impact may shift when adding or removing a suppressor, though quality mounting systems minimize this. Zero your rifle with the suppressor attached if you plan to shoot suppressed regularly.
Maintenance and Lifespan
Most suppressors do not require periodic cleaning.
User-serviceable suppressors can be disassembled for cleaning. All rimfire suppressors and most pistol suppressors accumulate lead fouling and require regular cleaning.
Sealed suppressors cannot be disassembled by the user. Most rifle suppressors are sealed because high-velocity centerfire ammunition produces less fouling. These typically do not require routine cleaning.
3D printed suppressors are typically sealed and follow similar intervals to traditional sealed cans, with one exception. Porous designs like PTR's VENT line require cleaning every 1,000-1,500 rounds because the titanium foam structure accumulates carbon faster than traditional baffles.
Quality suppressors last for thousands of rounds with proper care. Manufacturers typically offer warranties ranging from lifetime to limited years.
Key Takeaway
Suppressors reduce gunshot noise by 25-35 dB, bringing most firearms to hearing-safe or near-hearing-safe levels. They do not create silence. They provide meaningful hearing protection while maintaining firearm functionality.