Making the .25 Edgun quiet, easily and inexpensively…
The key to the Edgun .25 making less noise is reducing the air pressure at the muzzle. There are a few ways to do this without engaging in exotic baffle designs, or spending money on an aftermarket shroud or moderator.
Here’s how it’s done:
The first step is to remove both the baffle cover, which is unscrewed counter clockwise, by hand, then removing the bottom shroud by removing the barrel bushing/vent nut. Then you can easily enlarge the existing vent holes at the rear of the Edgun shroud with a variable speed hand drill. I made my lower shroud vent holes 2.0mm in diameter:
You can go larger if you wish. If you go too large and begin to hear air “whoosh” out of the vent holes when firing, just wrap some felt around the inside of the shroud, behind the vent holes, to slow the air down. You can touch them up with the tip of a permanent ink black felt tip Sharpie. This is how they look when done, but before the Sharpie touchup:
The next step is to increase the air flow from the front of the Edgun to the rear of the shroud. Now on the R3 this is a bit more complicated because the shroud comes in two parts, so I will concentrate on the R3. Unscrew the top shroud, baffle cover, taking care to remove it easily because the O-ring can be damaged on the threads. Be sure to put silicone grease that O-ring before putting it back on. Note the bottom shroud, and barrel, are held in place by a 19mm nut with vent holes in it. It unscrews easily, counter-clockwise, with a common metric wrench:
After it is taken off, you then enlarge the holes in the nut with a variable speed drill. I went 2.5mm, you may choose to go smaller, but not much larger, as the hole diameter affects the strength of the nut.
After this is done, you simply replace the bottom shroud, then the barrel bushing, being certain that the bottom of the shroud is properly placed OVER the rim of the permanent cone shaped breech attachment. If you ignore this step, you will bend the bottom of the shroud when you tighten the nut…note the bottom of the shroud sitting flush against the cone shaped breech attachment in this picture. The hidden rim inside the shroud is about 1/8″ or so tall, but it must have the shroud placed evenly over it before tightening the nut. When you lift up and remove the bottom shroud, you will easily spot it, as the cone shaped breech attachment remains in place:
Finally, there has been much discussion regarding how much torque must be used to tighten the nut that holds the barrel and bottom shroud in place. This is not a difficult process. First you obtain a Russian Torque Wrench…see below picture:
Placing the 19mm wrench in this handy grasping tool, you tighten the nut to where it is snug against the shroud, then you go roughly 1/2 turn further. That’s all it takes. Remember, this is thin and fairly soft aluminum and will strip threads or bend rather easily. AND…if you have placed the bottom of the barrel shroud over the lip of the cone shaped breech attachment, you will not have bent, or dented, the bottom of the shroud.
Replacing the top shroud (baffle cover) is easily done, just be careful sliding the cover over the O-ring using a light downward pressure and clockwise screwing motion until it gets past the threads on the cover. Snug it up hand tight, no more.
That’s it! You can expect at least a 50% reduction in muzzle blast, which on the Long Edgun makes the hammer slap the loudest noise emitted when shooting the gun. It costs nothing, takes about 1/2 hour, a couple of metric bits, and a variable speed hand drill. Take your time. The existing holes will guide the bit if you proceed slowly, especially when starting the new hole.
Now, for that hammer slap…I’m still working on that one.
Regards,
Kindly ‘Ol Uncle H 😯 😯 t
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Syn,
I placed the sound meter about six inches from the muzzle to the right. It was about two inches below the muzzle. I rolled up a towel and used it as the back stop. I knew the pellet was going to penetrate the towel so I placed my duct seal trap behind the towel. That way I would only measure the muzzle blast and not the impact.
I pretty much got all the info I needed. I’m done and I will be returning the shroud and meter.
Thanks for all your help,
Gabe G.
The carbon fiber shroud measured 67 dB without the LDC attached.
With the LDC attached, the measurement was 65 dB.
Interestingly, the one piece, aluminum shroud by Clague measured 65 dB…but in real life, my ear said it was a tad louder.
Hoot’s readings:
Factory modified= 69 dB
Carbon no can= 67 dB
Carbon w/can= 65 dB
Aluminum= 65 dB
Carbon w/can = aluminum w/out can…
Edgun w/ modified OEM shroud – 68 db
Gabe’s reading is a 1dB difference with the factory modified shroud as Hoot got, and 3dB different for the aluminum reading that Hoot got…
Hey Gabe, can you give us a run down of how you set up the meter?
While a meter may not be worth a shit for this, it is showing the relative difference between the various readings taken under the same conditions. If a decibel meter says one sound is louder than another by 5dB (less than 10%) i’m going to have to accept it. It’s like putting a 24 grain pellet in one hand and a 26 grain pellet in the other and trying to determine one is heavier. NOBODY is going to get it right with any real consistency. The scale will tell you which weighs more even if it isn’t telling you the exact weight.
Some people hear higher frequencies as “louder” while other hear lower frequencies as “louder”. Doing the “hey does this sound louder than this” test is like asking a kid which flavor of ice cream is better. Waaay toooo subjective to be accurate.
I have some really nice sound equipment (mixer and microphones) I think I may need to record a few shots from the EdGun and the Cricket and post the waves, decibel meters are not really made for doing this. What we need to see is the shape of the sound and the levels of the various frequencies involved.
Cell phones, video cameras, Radio Shack sound meters, might as well be suing a potato hooked up to a dishwasher. 😆
That sounds a lot more realistic,as it is louder than a Marauder and to reduce a guns report by 25dbs is quite something, if my Mrod was 85 I would put them closer to 87 than 67, they were definitely louder than the Marauder but not by a huge amount, Neil.
I would have to agree, my standard edgun is some where around the 90dB, would be interesting to see the designs of these shrouds too.
By the way Gabe I also shot the gun inside the house and asked my wife her opinion, she had no idea what shrouds were on the gun, the first was Horaces modified shroud, she said my god that things loud, then I slid on my one piece and fired it, she said oh thats a lot better, that is a lot quieter. I am just baffled as to your findings, they just do not seem in line with Horace’s or my own. I guess maybe some people are more perceptive to sound at certain frequencies because to my ears there was no comparison between the 2 and I still place no faith in the cheap meters used by a lot of shooters, I do not know many guns that can claim a 65 to 68db reading. The best I ever achieved was 66dbs on a Pneuma and that was with a large can and a lot of work, literally the gun being cocked gave the same reading as it being fired and I know I could not make that claim for any of these, including the 2 piece shroud, Neil.
Gabe I have to say I am completely confused by your findings, when I tried the single shroud it sounded considerably quieter than the factory shroud and not much louder than the 2 piece shroud. Even Horace had said the same thing to me in his findings, he told me he thought the one piece was not much louder than the 2 piece and both were considerably quieter than the factory shroud. I am concerned about the placement of the meter and where you had the children stand, with the enlarged holes at the back of the shroud it seemed to be very loud to me as the shooter, maybe this helps explain the difference in the readings, if more noise is coming out of the rear of the shroud. I never put a huge amount of faith in DB meters, as Horace had said his readings were in the mid 60 DB range which I find hard to believe, not his readings but the meter readings. I have a .22 Mrod that measures 85 DB on my meter and I have a fairly expensive meter and that also seems to be a standard reading for Marauders, and I know the Edgun is not as quiet as a .22 Marauder. So I am not fully convinced by these readings. I personally prefer to believe what I hear and not what the meter says, I can detect differences in sound quite clearly and to my ears there was no contest between the shroud Horace sent me and the one piece I made.
Have you done the modifications to the rear of the shroud? If not then maybe that was why his shroud sounded louder to me, because the shooter is closer to the air being vented out of the rear of the shroud? If you have done the mods then I just do not get your results? All the best, Neil.
Decibel wise those are all very quiet as airguns go – getting to the point where the pellet impact noise may be louder and they haven’t figured out a way to quiet that down on vermin when you get over 30 FPE or so. I think one will have past point of diminishing returns to pursue it much further. :horse:
That looks so cool!
I decided to test the guns again but a little different this time.
I recorded my edgun with my Iphone and measured the sound using the db meter. I played the sound file and recorded the db.
Here are the results:
Cricket w/ 16 in NC shroud – 65 db
Edgun w/ NC one piece shroud – 68 db
Edgun w/ modified OEM shroud – 68 db
I still think the OEM shroud is little quieter than the NC shroud. The NC shroud seems be more snappy. What I can say for sure is that there is a difference in the report between the less powerful cricket and the edgun. The edgun just “feel” stronger as though it is pushing more air or creating more powerful sound waves.
I can’t seem to upload the sound file to my computer. I would like to share them with you. PM me if you want to here them. I think they only open with apple devices so if you have an Iphone, etc.. I can email them to you.
thanks for reading,
Gabe G.
It must be remembered that different people hear different frequencies differently. So what may sound “snappy to you may very well sound more muted to someone else. So what may sound quieter to you, may very well be the opposite to the next person. 😉
KnifeMaker
Naser,
That looks so cool!
I decided to test the guns again but a little different this time.
I recorded my edgun with my Iphone and measured the sound using the db meter. I played the sound file and recorded the db.
Here are the results:
Cricket w/ 16 in NC shroud – 65 db
Edgun w/ NC one piece shroud – 68 db
Edgun w/ modified OEM shroud – 68 db
I still think the OEM shroud is little quieter than the NC shroud. The NC shroud seems be more snappy. What I can say for sure is that there is a difference in the report between the less powerful cricket and the edgun. The edgun just “feel” stronger as though it is pushing more air or creating more powerful sound waves.
I can’t seem to upload the sound file to my computer. I would like to share them with you. PM me if you want to here them. I think they only open with apple devices so if you have an Iphone, etc.. I can email them to you.
thanks for reading,
Gabe G.
That printer is too cool. :8:
Ok,
So I just opened up the holes on the front from 2mm to 2.5mm & I designed 3 different spacers with different hole sizes, starts with 4mm and goes down to 2.5mm & printed them and I dry fired a couple of shots & it does sound better, I will have to try shooting using pellets and see how it works out later.
I leave you with some pictures.
Meech,
I would run the meter C Weighted and on FAST with the number set on 70 (or 60). You could also try a set on A Weighted and FAST.
The meter is rated +/- 2db at 114db, so relatively speaking it fairly accurate (+/- 1db). One or two decibels isn’t a lot when you are around 70db.
Try pointing the meter at the muzzle from about 1′ & 3′ away (out of the pellet flight line of course) and pointed at 90 degrees to the pellet’s path about 1′ & 3′ away. This will give you a few different ways to measure the levels to see if there are any differences in the various test shrouds…
Did you get one without anything on the barrel??? 😐
Good job measuring the sound. I also used the kids and my next door neighbor at a 45′ angle to the front at about 50 feet to get a realistic opinion. Basically, all of my moderated guns are pretty quiet for the size of our lots, etc. (we all have several acres at least and many acres of common ground heavy woods) according to everybody. No idea on dbs. I used Paul Capello who sound tests many of the more recent guns on Pyramyd Air for a comparison. He gives some pointers on getting accurate sound measurements in one of the videos but admits they are not scientific. Of course the right equipment is paramount. I think he considers anything under about 105 dbs in the stealthy category minimally. Here he does a AA S510. I own an AA S510C and added a NC on the end (even though it didn’t really need it at my house). I think the Marauder 22 is down around 65 db if I remember correctly but I am old and that may be way off. 🙂
Sound measurement at very end
interesting. 😕
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What you are saying is not true, good quality meters use weighted metering and read at different pitch levels so they read dbs at different pitches, you might read with it set to A and get 65 dbs and read it set to B and get 75dbs, better meters also have a fast and slow response, if you do not have settings on the meter and just use a phone or cheap meter the readings are not worth squat. I have used cheaper meters and got different readings from them without doing anything or making any changes. I do not put any store in DB readings unless done with high quality equipment in a controlled environment.
Gabes shroud has also been modified differently to Horace’s, he has larger holes than Gabes shroud and it sounded very loud to me and anyone else who heard it. While I doubt the db readings I do not doubt what he is saying now I have seen his mods are totally different to those Horace made. But without hearing the 2 shrouds live I can not really comment, maybe by adding the holes to the back of my shroud will make it quieter still, but I leave this kind of thing up to customers to do. I just do not have the time to play with this kind of thing whereas some of you seem to have plenty of time on your hands, keep playing and maybe you will find the perfect solution, Neil.