Airguns are significantly quieter than traditional firearms, but what is considered “loud” for an airgun? That’s what we are going to talk about today because it’s an important topic that has left many airgunners confused. Let’s unravel this mystery.
Measuring Airgun Noise
When you see DB (decibel) numbers on a website or review, what exactly was measured? Were measurements taken in a scientifically controlled and sound dampened environment? Where were the sensors placed, and how many were there? Did they measure the mechanical noise or the actual shot noise?
These are all questions we need to ask whenever we see a DB number posted with an airgun review.
Measurements that are taken outside of a controlled environment, and without calibrated equipment, it is not very scientific. DB numbers can be based on many factors like sensor placement, elevation, objects near the testing area, etc. Needless to say, a uniform standard measurement has not been set across manufacturers.
Types of Noise
There are two, maybe three areas of noise that your airgun will produce: mechanical noise, shot noise, and impact noise.
Is what you’d expect it to be, the mechanical sound generated by your airgun. Take your typical spring or gas ram airgun. There are several moving parts under the hood producing a lot of noise once that trigger is pulled and they slam forward. All this happens right in the shooter’s ear and is often seen as making the gun “loud”.
PCP airguns have something similar called hammer “ping,” which is the sound that the air tube can make, almost like striking a bell, which can seem to be quite loud to the shooter. Now, if you are target shooting in your backyard with neighbors close by, these may be very serious things to consider.
Shot noise is the sound produced from the muzzle as you take your shot and what most shooters are looking to control. Spring guns produce very little shot noise due to the minimal air volume and the lack of continued expansion. You may get a supersonic crack with some high powered .177 airguns shooting over 1100 FPS. This noise is the projectile breaking the sound barrier, and there’s no way to control that. It’s always going to be loud.
It’s a very different story with PCP airguns, however.
PCP airguns move a much larger volume of air at higher pressures. Additionally, the valve may allow the air to continue to expand and drive the projectile out the barrel, further increasing the loudness of the shot. Some PCP, specifically big bore airguns, can come very close to the same sound levels as a traditional firearm.
Knowing and/or controlling the sound level from the report of your airgun becomes essential not only for keeping good neighbors, but also when hunting. Because most airguns operate below the sound barrier, your game is going to hear the shot before the projectile gets there. A loud shot allows the animal to jump the shot resulting in injury rather than a clean kill.
The last “noise” consideration applies to target shooters. Today’s modern, suppressed, airguns are very quiet with little to no mechanical or shot noise at all. Your target may be another thing altogether. Steel pellet traps are excellent at stopping pellets, but they are also very loud. Hay or other soft targets may not be suitable for stopping pellets from high-powered airguns, but they are quiet.
Before you start target shooting in your backyard or wherever you are shooting, please consider what’s going to be the right solution for your backstop based on your environment. You may also need to research any legal requirements in place for your specific location.
We thought it would be practical to demonstrate how this plays out using a typical “suppressed” gas ram airgun. Spring guns are the most popular airguns purchased, and many have suppressors and tout just how quiet they are.
We took three measurements to demonstrate just how the DB number changed based on sensor location:
Location 1 – Right at the shooter’s ear
We aimed the sensor directly at the action of the airgun at a distance of 24 inches. The highest DB measured was: 101.8 DB
Location 2 – Shot noise
We set the sensor at a 45-degree angle and 10 feet from the muzzle of the rifle. The highest DB measured was: 97.9 DB
Location 3 – What the game may hear
We set the sensor at 25 yards and shot past it. The highest DB measured was: 76.7 DB
What Does this Mean?
We conducted our tests at 4600 feet elevation, and in our experience, the higher elevation seems to minimize the shot noise heard due to the thinner air. You may have higher readings at sea level. Additionally, the measured sound level existed for a fraction of a second, making it seem a lot quieter than our gear picks up.
From this simple, very unscientific demonstration, we learned that 101.8 DB, you are mainly hearing a lawnmower in your ear for that split second. At 10 feet, the sound is reduced by about 25% and is like an electric drill for that fraction of a second. But, when you get out to 25 yards, things change considerably. Both the mechanical and shot noise is about as loud as a quiet toilet flush. That reduction becomes more significant the further away you go. Our testing conditions were a bit windy, so trying to take measurements past 25 yards would probably not be anywhere near relevant as the wind noise would possibly measure higher than the shot or mechanical noise.
To wrap things up, keep in mind that airguns, specifically spring or gas ram powered small bore airguns, are pretty quiet. So if you have a 50 to 75-foot buffer from your shooting position, you will probably be OK. Consider your surroundings and what kind of backstop you’ll be shooting. Most small-bore PCPs are even quieter but make more power, so that backstop material becomes even more critical. Big bore airguns pose a unique challenge and really should be shot only at a range or in the field hunting.
As always, if you have questions, just reach out to us here at Airgun Depot. We are here to help!