The silencer issue

by B.B. Pelletier

Curtis asked a number of questions about silencers. Although I think the answers have already been given, they are perhaps not worded exactly as he asked the question, so today I want to spend a little time on the subject. Before I do, here is a linked bibliography on the silencer issue.

Airgun silencers: What’s the big deal? Article by Tom Gaylord
Airguns and noise Blog Feb 8, 2006
Guilty! Jury finds airgun silencer illegal Blog July 18, 2006
What about a silencer for your airgun? Blog May 2, 2005

CURTIS’ QUESTION
This is (very) off-topic, but I wonder if you would be so kind as to address an air gun topic that is “loaded” (pun fully intended). This regards the sensitive issue of air gun “silencers”, “moderators”, “shrouds”, “dampers”, or whatever name that people care to call these devices. Specifically, my inquiry involves an assertion by Dr. Beeman (“Silencers on Airguns” -an article that can be found on his website) that shrouds, moderators, etc, besides being (in his opinion) illegal, are also, according to him, ineffective in reducing the report of any “springer” type of air rifle.


I am not concerned here with the legality issue, but rather the assertion that these devices do not work on airguns. His logic is that though the moderators may be effective on CO2 guns and PCP’s because of the fact that they involve allowing the slower expansion of a large volume of air rushing from the gun upon discharge, that this is NOT the case with springers since springers merely use a cusion of air as a medium for transfer of the energy of the expanding spring to the pellet, and so, in his opinion, the moderator does nothing to dampen the sound of the spring air rifle.
This seems contrary to both common sense as well as observation to me for the following two reasons;


1) I notice a definite difference between my (very loud) Webley .177 Tomahawk and the sound of a TX200 in the same caliber being discharged (though I do know that the Tommy is more powerful) and;


2) Noise inside of a structure, such as a home, can be “dampened” or moderated by the use of special building techniques involving more insulation and a second layer of wallboard held to the studs by special clips which allow the wallboard to move and cancel the transfer of sound.


It seems to me that dampening the noise from an airgun would similarly involve allowing vibrations to be muffled by an expansion chamber (such as a moderator or shroud), and that the noise of the rifle firing is not solely generated by a large blast of air such as issues from a PCP or CO2 rifle. For that matter, my QB-78 is very quiet and has NO moderator or provision for sound reduction other than a rather long barrel, yet it is very quiet. Further, it seems that these devices would not be so popular in the countries of Europe where they are legal, if they were not effective. I am very interested in reading your opinion on this matter. Thanks for putting up with my (verbose) and lengthy rant on this matter, and thanks also for your attention and consideration.

ANSWER
Dr. Beeman is correct about the “noise” of a spring gun. Most of it is transmitted through the bones of the shooter’s face, so the sound is much louder for the shooter than for those standing close by. Thomas Edison was deaf and listened to the phonograph he invented by biting on the wooden case of the instrument, so he was intimately familiar with the sound conductive properties of facial bones.

It is possible to muffle the muzzle report of any airgun with a silencer, however. As quiet as spring guns are, the TX200 is further muffled by the use of a shrouded barrel containing a baffled silencer. It works, but the payoff is very slight. The TX200 is also a very smooth spring gun, and that, alone, reduces the noise. So, yes you can silence a springer, but why would you want to? An exception is a gas spring gun, whose gas-driven piston produces a small crack of sound upon discharge. But a well-adjusted spring gun is already very quiet (EXCEPT TO THE SHOOTER!). Curtis, you need to let someone else shoot both guns and you listen to the report. The TX will be louder than the Tomahawk, but not by as much as you think.

So why is Curtis’ QB78 so quiet? Because by the time the pellet exits the muzzle, the gas pressure has dropped relatively low, and it doesn’t have enough remaining energy to make a loud sound. This is the same reason all spring guns are quiet. Because they use so little air, there is no energy remaining by the time the pellet leaves the muzzle.

I’ll leave you with this thought. In the 1980s, certain printers were extremely noisy. The Lexitron word processor printer was so loud (either 92 or 96 dB, as I recall) that it had to have an acoustic shield over it at all times. It was an impact-type daisy wheel, if that means anything to you. But times changed. Today’s office printers are so quiet that they cannot be heard in most offices. They use different technologies, of course, but the fact is that they’re quiet. You could lower their noise signature even more by putting an acoustic shield around them, too, but why would you want to?

29 thoughts on “The silencer issue

  1. Sure – To me, the reasons you would want to are threefold:

    1)A St. Cloud, MN firm did some testing on springer noise prodution . At 6 feet
    (noted as ‘point-blank’), the db range of the 15 spring guns listed in the test was from 88 to 94, with only one below 90. Yes, I know it is an exponential scale. Regardless, we aren’t talking whisper-quiet, here.
    2)Cool factor. Ever seen a James Bond movie? Of COURSE you want one!
    3)The BATFE says you can’t have one. Again – Of COOUUURSE you want one!



  2. B.B.

    Sorry this is off topic. What is you say so about laser bore sights? do they work just as well as if you were to sight a scope in just by shooting it? If so, why dont many people use them?


  3. Sticky,

    Airgunners don’t neewd bore sighter devices because they can sight in at 10 feet. So they are a waste.

    Now for big bore, they could be useful.

    B.B.


  4. RE: bore sighting:

    BB have you ever seen ballistic tables for pellets like the ones in the back of the Speer no. 10 and later manuals? The scope is always way above the barrel, it would be useful to know the pellet’s path.



  5. out of curiosity, is your whiscombe as quiet as your tx? looks to me they are both well made, so it seems like a good comparison between silencer and no silencer.


  6. bb
    ive never heard a real silenced firearm. do scilencers work as well as they portray in the movies. for exampe someone gets shot with a silenced gun and the guy standing 10 feet away doesnt hear a thing. is this true or grossly exaggerated?


  7. dm20,

    No the Whiscombe is a little noisier. Although it doesn’t recoil, there is a hint of vibration. The TX has none.

    B.B.


  8. Silencers,

    Well there are all kinds of silencers. There are some high-tech ones so quiet that there is no audible noise beyond 20 feet (not loud enough for most adults to hear), but the strike of the bullet is very loud.

    My .22 silencer isn’t that quiet. My 10/22 sounds like a quiet CO2 rifle.

    I have (not) heard airgun silencers so quiet all I heard was a musical sound made by the hammer spring, followed by the strike of the pellet.

    B.B.


  9. cool thanks
    another question- i want to start shooting in my cellar. i have an open space through 2 rooms about 40 feet long. im looking for a quiet accurate pistol or compact rifle. also i dont have that bigg a buget to work with. i was thinking of coustom building a C02 pistol on the crossman sight but it seems confusing and expencive. also i am left eyed. any suggestions?


  10. any device capable of reducing a firearm discharge, by even one decibel for one shot, is subject to the strict regulations of the silencer laws, regardless of to what it is, or is not, attached. So, although BATF has no jurisdiction over airguns, they do have jurisdiction over devices which could be used on a firearm – and by that amazing federal definition, silencers are FIREARMS!

    Does that mean a pillow is a firearm?


  11. B.B.,

    More question(s)about the talon, lol. So, i’m not interested in the power of the condor, at all. Im also not interested in the quietness of the Talon SS. I called a couple places asking if they would sell me a talon SS with the 24″ barrel installed for a little more money but not full price of SS + 24″ and keep the 12″ barrel and cap cuz i dont need it. One guy said he could sell me a condor with a standard tank and it would be the same thing and cheaper, I read your article on this subject and it agrees but my question is the hammer weight. The condor has a heavier hammer weight, how will this affect the configuration the guy is offering me? Will it cause any damage? Will it affect the “air efficiency” that I’m after? I’m not good at phrasing my questions. Instead of turning my condor into an SS id like to turn it into a 24″ SS so can I just replace the tank?


  12. Hello B.B.;

    Thanks for addressing my questions in such great detail. I was stunned to learn that Thomas Edison was deaf- I never knew that. Lest any of your readers should get the wrong impression, I would like to make it clear (even if it is after the fact) that my letter to you was concerned with the possible theoretical sound reducing advantages of moderators on air guns. I do not advocate breaking any laws by actually constructing a device for the purpose of quieting the discharge of any gun-whether it be an airgun or firearm. My email was a solicitation for information and discussion ONLY. Again, I thank you for the information and answers to my questions.

    Regards,

    Curtis


  13. B.B.;

    I just read “what about a silencer for your airgun?” and I just had to come back to you with one more question on this topic which your article inspired. That question is this; in your article you seem to be saying that a “shrouded barrel” (as is installed at the factory on the TX200 or on some PCP rifles), is not the same as, or does not fit the description of a “silencer”. You go on to note that the “Air Force” company invented this item which “strips much of the muzzle blast from the barrel”. Am I to gather from this that the BATFE would NOT consider this item to be a “silencer”, and if that is so, then why not? Doesn’t it do essentially the same thing that a separate, removable “traditional” silencer with baffle construction does? I’m just curious about how the BATFE would view this because, if they DO consider the two items equivalent, then every TX200 or B40 owner out there who does not have a “tax stamp” for his or her factory made “shrouded barrel” rifle is in jeapardy of being jailed for “owning a silencer”, correct?
    On a different note, in a prior answer to a question that I had for you concerning a possible CO2 rifle purchase for hunting, you mentioned that what I really want is a PCP rifle. Well, I have come to the conclusion that you are probably right. So,… I am eyeing up the Webley series of PCP rifles (in 22 caliber) and, since you do not have a review of any of these on the Pyramid web site, I thought I might ask you if you had any experience with any of the Webley PCP’s (I am fond of Webley’s products, even if they did go under!) and if so, what your opinion of their PCP rifles is. I am looking particularly at the 2-shot model that they sell, called the “Webley Venom”.

    Regards,

    Curtis


  14. Left-eye,

    Why build a gun when so many are available at bargain prices? I don’t know your budget, so it’s impossible to recommend a gun to you.

    As for the left-eye dominance, it’s cheaper to shoot left-handed than to convert sights. A Daisy 853 is close to ambidextrous and also very accurate. Is that in your budget?

    B.B.


  15. Pillow,

    Your argument is one that has been debated to death. The usual device is a 2-liter pop bottle.

    This is why there are judges in the courtroom, and, no, that doesn’t always work, either.

    B.B.


  16. The.Man,

    You are treading on thin ice. The guy who can sell you the “Condor” with a standard tank is doing something wrong. And the extra striker weight of the Condor ruins the adjustability of the whole setup.

    There are a lot of “experts” out there who have ruined more airguns than they have fixed. There was another “guy” sellig trigger modifications who voided the lifetime warrantys on more than 50 airguns for unsuspecting owners.

    My advice is to stick with reputable dealers who stand behind what they sell. No mix-n-match!

    B.B.


  17. Curtis,

    If there is nothing that can be removed from the airgun and affixed to a firearm to reduce the report, there is no silencer.

    I once wrote a blog about using a house as a silencer, by shooting out the window. BATF doesn’t sieze houses, either.

    Webley is a fine name in airguns, but the Raider Venom you mentioned is made by FX of Sweden. Therefore, it also exists under many other brand names as essentially the same gun.

    Venom is a brand name Webley has applied to many different guns they have sold over the years. This gun you are looking at is actually a Raider, which has also been sold as a Rapier in the past. And it’s been sold under the RWS name and the FX name, as well as by Webley.

    That said, the Raider Venom is a fine air rifle – one you would be proud to own. I have tested similar guns under several other names over the years, and they always performed well. Buy it with confidence.

    B.B.


  18. I believe you have one little error in this report. It wasn’t Edison who was deaf (at least he wasn’t in his active years…maybe he lost hearing in his old age like many of us do.) It was his WIFE who was deaf.



  19. BB,

    According to you, if a PCP makes a loud noise, it means the PCP air is not being use efficiently, meaning some of the gas is wasted. correct?



  20. Hello.I currently own a Crosman Quest 1000 which I bought about 2 weeks ago.While it seems to be a nice rifle,it seems to be lacking something.I am considering buying a Gamo Shadow 1000 and would like an opinion about whether or not it would be worthwhile.I am fairly new to adult air guns.


  21. big ken,

    If you already own a Quest, a Shadow may seem very similar.

    What are you looking for? Build quality? Accuracy, Power? All of these?

    B.B.


  22. I’m from Canada where airguns toe a tedious line between being classified as a firearm (greater than 152.4 meters or 500 feet per second) AND a high muzzle energy (greater than 5.7 joules or 4.2 foot-pounds) which means that they are subject to the same rules and regulations as any other firearm; or conversly, if they fall below either of these numbers they are deemed by the Firearms Act and the Criminal Code not to be firearms and are exempt from all licensing and regulation.

    In addition, silencers for firearms in Canada are illigal. So to get this straight, an airgun such as Walther’s CP88 for example is not classified as a firearm in Canada. Silencers for this gun are made and sold in the UK. My question to anyone who might know or has any thoughts is this:

    Silencers for firearms in Canada are illigal, but the CP88 is not a firearm. Therefore is a silencer made for, and used on a CP88 legal?

    mike


  23. Beeman is way off on his claim about bone conduction. Most of the noise from higher powered airguns comes from the muzzle, and that is not transmitted through bone conduction. Spring guns over 12 ft-lb have a significant amount of impulse noise from the muzzle that is not accurately measured by consumer sound level meters, or professional equipment that measure dBA SPL.

    Most SPL recordings are done by people who have no understanding of what they’re doing. Is is the measurement made on-axis? Off axis? Is it a standard 1 meter away? Is it A weighted, B weighted, impulse weighted? If I don’t see full specs and a calibration statement I assume the reported figures are meaningless.


  24. Silencers are legal if you go through the correct channels to get one. I've looked into the process of purchasing a silencer. You have to apply to the BATF for permission, on the form you must have written permission and/or approval for the silencer from your local Sheriff, pay 200$ document fee (if your request is turned down you don't get the money back. Apon approval you may purchase a silencer from an approved manufacturer and it will be serialized and registered to you for life (or until your permit to own one is revoked, but you CAN legally own one. Here is a place you can read about how to get a silencer the legal way. http://www.silencerresearch.com/Silencerguide.pdf



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