Decibel Ranking of Airguns

DISCLAIMER
Before you view the results, we should explain our motivations for conducting the decibel tests and the conditions that existed during the testing phase. First , the motivation for conducting the decibel tests. For starters, let me say that we (Kevin and Craig of Straight Shooters) are not engineers. Kevin has an ear for music, Craig could not tell the difference between a bing and a bang. Why is that relevant? Because many of our customers want to know how loud one gun is compared to another. Our goal was to provide a relational look at how loud various airguns are when compared to each other. We were not as concerned with the actual decibel reading as we were to the relationship between the guns.

Our tests were simple and practical and any of you can conduct these same tests. We went down to our local Radio Shack store looking for sound measurement devices. The clerk pointed to a decibel meter and said this is what the police use to measure noise and that was good enough for us. Off we went looking for the proper place to conduct sound tests. We look for an open field surrounded by woods which would form a natural amphitheater without echoes. After finally finding an excellent location, we set up the decibel meter at various distances. At distances of 2, 10, 25 and 50 yds, we fired a series of rounds from each gun. We recorded the numbers and averaged them out to get the decibel rating for each gun. Since most of these gun tests were conducted at the same time and same place with the same weather conditions, we concluded that the readings would give us a scale from the loudest to the quietest. We also measured some common non-gun sounds that would be recognized by most people in the hopes that they would convey some sense of what the decibel numbers from the gun tests actually mean in terms of sound.

AIR RIFLE SOUND TESTS

As I answer questions emailed or phoned in to Straight Shooters, it is very evident that airgunners are immensely interested in two areas of airgun performance. The most common question deals with the power of a particular airgun model. That usually translates to the guns velocity rating. The second concerns the noise level of a particular airgun model. The sheer number of questions about the level of sound/noise led us to conduct the following sound tests on a number of popular airguns.

The tests Craig and I conducted were chosen to respond to the nature of the questions we are asked most commonly about sound and noise. These questions usually fall into the following categories:

· Is XXX gun quiet enough for target shooting in our basement without disturbing the whole family?
· Is XXX gun quiet enough to let me get more than one shot at my quarry without alarming it if I miss?
· I don't want my neighbors to hear me shoot. How loud is XXX gun?
· Which gun is quieter? XXX gun or YYY gun?

In response to these questions, Craig and I tested 19 well known spring airguns at four distances. Point Blank,
10, 25 and 50 yards. We felt that the sound levels captured at the Point Blank and 10 yard ranges would answer the first question. The 25 yard and 50 yard results would provide information for answering the other three questions. All decibel tests were conducted using "A" weighting instead of "C" weighting. "A" weighting is generally used to record the decibel level of a single event while "C" weighting is used to measure continuous noise levels (crowd noise, music etc.). Strings of 10 shots were then averaged, yielding the results below. Tests were conducted outdoors in an open field on a partly cloudy day with winds of 5-10 mph.

Before reading you should be aware that sound/noise is a quite subjective to human hearing. One sound can seem louder than another sound, even though it may not actually measure any louder on a decibel meter.
We don't claim to be acoustical engineers nor are we trying to get into a major scientific discussion. But a simple test shows that bass tones from your stereo carry farther than high tones. The point here is that some sounds seem louder or quieter to us even though they measure the same decibel level. Our idea was to simply find out which guns measured the loudest, the quietest and which gun would be most audible to other people at various distances. What specific animals or birds hear at the same distances is anyone's guess. We took decibel readings of a number of common events to provide a basis of comparison. The following can easily be duplicated at home. All comparison tests were done at a distance of 6 ft.

Testing Results
Point Blank (6 ft) - 19 guns tested. All placed within 7 decibel levels in this category. 1st place = Quietest. 7th place = Loudest
10 Yards (30 ft) - 19 guns tested. All placed within 9 decibel levels in this category. 1st place = Quietest. 9th place = Loudest
25 Yards (75 ft) - 19 guns tested. All placed within 9 decibel levels in this category. 1st place = Quietest. 9th place = Loudest
50 Yards (150 ft) - 19 guns tested. All placed within 8 decibel levels in this category. 1st place = Quietest. 8th place=Loudest