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
All Replies
If you decide to drill holes on the cover, try to make them on the bottom of the tube. That way if you need to fill them with epoxy, they won’t be visible.
Gabe
You’re assuming that I’m that intelligent. Too late. But no harm done, looks fine.
I vented the air chamber between the nut and the first baffle.
I carefully measured 27mm up from the threaded bottom of the baffle cover, and drilled eight holes, spaced 10.3mm apart, going around the shroud tube, using 2.5mm holes.
Did it make a difference? Yes… but we are beginning to deal with diminishing returns as regards venting the shroud.
My decibel meter is not spot on, but does tell me the max dB. I hesitate to drop any numbers because it’s windy today and an exact reading is very difficult to obtain. Using averages of three shots, the meter indicated the dB’s went down from this morning’s in the front of the muzzle readings, but went up slightly when measured from the sides of the muzzle. Not much, but a definite indication that less air is making it out of the muzzle, and more air is venting from the sides.
Did I gain or lose? Remember I’m 70 years old and my hearing is not as fine tuned as most of yours. I could not tell a difference myself, as far as volume is concerned. There was a difference in the harmonics and “pitch” of the sound.
Is it worth doing? Not as much as the original bottom of the shroud venting. We could see some very evident gains there. Not so much in this latest attempt. At this point I would say “…, it’s in the ears of the beholder” being that we don’t all hear the same thing.
It’s not a bad looking mod to the top of the shroud, but I only used 2.5mm holes. Not all that visible. I did not wrap the inside of the baffle cover with felt or mesh because there’s simply not enough room. And you do have to drill a couple of large holes in the sides of the baffle frame to permit the side shroud cover vent holes to exhaust air. Not a big deal as there is plenty of metal there to drill a fairly large opening for the vent hole to line up with.
This is as far as I’m going with the venting process. Further gains will have to be achieved through other methods.
Hey Hoot,
If you decide to drill holes on the cover, try to make them on the bottom of the tube. That way if you need to fill them with epoxy, they won’t be visible. Now that you have a baseline, you can compare before and after the last modification. In theory it sounds like it should work. I agree with you on starting with tiny holes.
Related topic:
After enlarging the holes on my tube, I noticed that the small amount of residue directly in front of the holes is no longer there. The residue spots were under the front of the scope rail and the air tube. This leads me to believe that the mod has reduced the air pressure exiting the holes.
Keep us posted.
Gabe
That’s pretty damn quiet Hoot. 😯
Would you happen to be using a Radio Shack decibel meter? I have one but either lost the instructions or it didn’t come with any.
Got this from eHow, the rest of the “article” is crap but I found this tidbit useful.
A-weighting lets you measure specific frequencies between 500Hz and 10,000Hz.
C-weighting measures the frequency response from 32Hz to 10,000Hz.
Select A to measure the sound in an area; select C to measure music sound levels.
After selecting A or C-weighted, choose a fast or slow response time.
Fast is used to measure peak levels and slow measures average levels.
Do not smoke it!
Thanks Linkan… I’ve always liked you best!
By the way… I got my Chinese decibel meter out, and my Edgun Long. 25 measures, at ten feet, to be 53 decibels from the side, and 54 decibels from the front.
This was measured outside on my deck. The ambient noise level out there averages 48 to 50 decibels.
So, not dead silent but certainly quieter than it was. No… I did not measure it before I modified it. I still believe the existing muzzle report can be reduced further. There is still a LOT of air exhausting the muzzle. My experience with the Cricket has shown that report can be reduced to near silent. My goal is the only remaining sound from the shot will be the hammer slap, which most individuals will not recognize as being associated with an airgun… at least not when heard from any respectable distance of ten meters or so.
The baffles Ed uses are not, in my humble opinion, the most efficient design available today. But Ed is not trying to make a silent airgun… we are. Since the R3 incorporates the baffles into a one piece barrel bushing/torque nut design, we are hard pressed to simply replace the staggered washer design he uses. Our path of least resistance remains in efficiently venting the compressed air before it exits the end of the shroud. There is one place left that might make a big difference and that is venting the shroud that covers the baffles. The question is “where”? Is it best done at the location of the first baffle, or the final baffle at the end of the shroud? I do believe the holes would need to be small in number and size. I might try six small 1.5 to 2.0mm holes and see what happens. Top vents seem to help the Hugget shroud, and that gives me confidence to press my luck a bit further
The idea of adding additional volume to the shroud is great, but we lack the means to produce such a device. It would solve our problem without a doubt. The only drawback is additional length. We might have a bit more to squeeze out of the OEM shroud.
More later….
Honorable Uncle
Until such time as I have my lathe delivered and my stash of material available and can prototype, test and produce these contraptions you’d better hold on to that hairy russian tourqe wrench if you’re in the need of a helping hand instead of lending it to bunch of shady characters.
And by the way, I’m not in habbit of sucking the nuts of bears nor do I recommend anyone else to do so.
It’s a sound old finnish proverb and stands true even today.
Regards
Evil & EDdie
Sent from the couch with the aid of my GT-N8000 via Tapatalk 2
Oh Linkan, how I miss you. You should comment in every thread even if it’s just a hello. :2:
Hoot! I have some K baffels laying in my garage. I will measure the size when kids are in bed sleeping …..
Do not smoke it!
Dr. Evil’s stripper idea is great. However, that would mean removing the first and/or second baffle to make room for the stripper. Even with the permanent mod, it make so much sense and is a worthwhile consideration. I would buy a stripper.
Here’s a quick sketch of what I was talking about:
If we can find an exact sized tube, have someone with a lathe cut the threads (ideal method of attaching tube), and add an end cap, we will have the front volume we are looking for. Along with the stripper idea, I think the .25 can be made super quiet while keeping a with the lines of the gun. Maybe Neil can build one 😕 .
Gabe
Hi,
To spare the baffle cover, a piece of aluminum tube can be used with the same dimensions. If thread cannot be cut, maybe a couple of set screws can be used to attach the tube. The set screws can bear down on the baffle nut to preserve the threads (where the baffle cover screws onto).
The key is finding a tube with the correct I.D. And an O.D. That will not touch the air tube. The new baffle cover can be longer than the original. An end cap can be pressed, epoxied, or secured with screws onto the end which will essentially create an final stage expansion chamber.
I’ll sketch it, take a pic and upload the design for illustrative purposes in a bit.
Gabe
like this, to direct or force as much air as possible back thru the holes and in to the shroud.
Send me but one, Dr. Evil….you, who own, operate, and prosper, from genuine mill ownership!
Here I am, at an advanced age, living on twigs, berries, acorns and catfish, deep in the woods, all the while trying to help my fellow man survive a harsh and noisy world…and not a single soul will lend me a hand…much less a “K” baffle!!!
I quote the most honorable Finnish hero….Baron von Ville: “There roams this earthly palace, an evil unlike any seen by man or beast…it’s name is The Doctor of Evil, aka Dr. Evil. Woe unto those who approach his dastardly web of intrigue and deceit, seeking solace, assistance, or advice!” Sir Ville circa 2012
While I cannot fully understand ancient Finnish warnings of creatures who do evil to humans…it would appear you are on the Finnish National Registry of Evil Beings…(FNREB)
That being said, I still don’t have a K baffle, nor a place to buy or have one made, that fits the Edgun. A problem which YOU could easily solve for those less gifted! (that being me…you evil swine!)
Are you ready to put your mill where your post is???? Are you? Huh? Huh? Well…..are you???
I close with these words of Nordic wlsdom…..“Sug aldrig klon av en björn, och inte heller kläm pÃ¥ den av testiklar!“
Kindest regards,
Uncle H 😯 😯 t
How about some kind of conical “airstripper” in the first compartment of the standard airstripper on the eddie?
like this, to direct or force as much air as possible back thru the holes and in to the shroud.
The below pic is NOT a picture of Ed’s baffle setup. His baffles are closer together, but it is somewhat similar. I have noted the proximity of Ed’s baffles is much closer to each other. This shortens the baffle stack, but reduces volume for gas expansion from the muzzle.
Having drilled out the OEM holes in the barrel brace/baffle stack nut, it reduces the noise by allowing gas to expand backwards into the empty rear shroud. Question: can even more air be directed back into the rear shroud? To do so would require larger holes in the nut (not really possible), or providing some mechanical barrier to gas release, forcing it backwards into the rear shroud, and reducing/slowing gas flow to and through the baffle stack. Below is one type of “I Baffle” easily built and installed. The question now is where to put it. Most baffle stacks have an expansion chamber. The baffles in the Edgun design lack any significant expansion chamber between the muzzle and the baffle stack.
The idea here is to determine how best to locate and permit the I Baffle to do it’s barrier work, and force even more air backwards through the nut holes.
It is one possible answer. One I shall examine closer tomorrow. I don’t have a mill to work with, so my efforts will be primitive in creating the extra baffle.
There is another way to reduce air pressure on the existing baffles and that is to put very small vent holes in the baffle cover, where the 2″ expansion chamber would normally be located, and permit reduction of final baffle gas pressure by venting it to the outside. This is a touchy matter, because the holes would have to be quite small to prevent a secondary venting noise from the new holes. However, note that the Huggett shroud has such vents located both in front and in the rear of their shroud. So, it is workable, but must be approached cautiously. Also, I anticipate some felt, fine steel pad, or other such strong porous material might be needed on the inside of these upper vent holes to muffle and slow the exhaust air through the new vents. I would anticipate the holes would need to be 1mm to 1.5mm in diameter, or about the size of Ed’s OEM vent holes at the back of the shroud.
Food for thought. I intend to explore this some more. Pics and results forthcoming if I can get the idea together, and hopefully reversible. Note: vent holes drilled in a shroud can be epoxy putty sealed, smoothed, and painted over with a satin black paint and will not show. I know this because I’ve done it before.
We shall see….we shall see…Remove an OEM baffle and insert the I Baffle, or find a place to fit it in…hmmmmm
Should front vent holes be located at the rear of the baffle cover, or in front of the very last baffle that releases remaining air out of the shroud???
Such off the cuff ideas can often stimulate more creative minds to produce useful thoughts…so don’t be shy, post your thoughts.
You shouldn’t. The baffles and tube are meant to deal with the exhaust; the compressed air released from the tank via the valve transfer port. The air that is used to propel the pellet up the barrel is substantial. It is also going very fast. This is where the baffles and mod tube come into play. They are supposed to slow the air and diffuse it. Just think about how the exhaust system works on a car. Same principle.
OT – I was under the impression that Hoot was Syn or vice versa all along. To me, very similar intelligences. Just my dos centavos.
Hey thanks man. So I ‘jetted’ the vent holes on the baffle shroud to 2.0mm and the vent holes on the baffle nut to 2.5mm. Not sure of improvement. How do you guys suggest the muffling material inside the barrel shroud?
Kekoa,
It’s easy to loose perspective. Tape the holes shut and shoot your gun to notice the difference. Or place a towel over the holes when firing if the tape is blown off. With my gun I can tell a huge difference. It also depends on the environment.
My benchmark is my .22 cricket with a Clague mod. My edgun is not nearly as quiet but close enough where I feel the gun was worth modifying. Besides, the ring of holes look hella cool IMO.
Gabe
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I’ve got an idea…
I can send Neil Clague the baffle cover and have him make a custom moderator, and thread the bottom, so it will fit on the barrel bushing/nut threads. I can easily dremel off the OEM baffle frame, just above the threads, still have the barrel secured, and be able to screw on a more effective moderator of a length of my choosing.
Since it would be screwed on, the vents in the nut and the lower shroud would still be effective and the NC moderator can work it’s magic. Neil can make the expansion chamber as long as I want it before he baffles the moderator. Hmmmmm…..perhaps something in carbon fiber…