Closed-cell foam to wrap gun with to quiet the pipe-ringing sound?

[Member 32425]

This is something that I have not experienced with my Maverick VP. Couple of questions for you:

• What caliber is your airgun?
• What are your regulators set to?
• What weight is your hammer?
• Which pin probe are you using?

Hi estarkey7.

I don't think anyone has experienced this except me and my shooting buddy. I'm just glad the horse's owner hasn't accused us of shooting AT his horse -- that has never happened and never will. We are both afraid that we might be wrongly accused of this every time the horse spooks from a ping sound 100 yards (or more) away.

I have an FX Maverick 30 caliber sniper (700mm barrel). The barrel I just now put in it is the 1:18 twist rate barrel so I can get better stabilization from heavier slugs (currently in process of tuning for nsa 54.5 grain slugs and I'll probably stick with this). The barrel that came with it is the 1:22 twist rate barrel that I used primarily with nsa 49.5 grain slugs.

1st reg 180 bar (set it a long time ago and it has probably settled down to 175-177 by now). 2nd reg 160 bar (set it a long time ago and really seems to like settling back down to 158). These are the original FX regulators that came on the gun. I know I'm pushing the 1st reg more than is specified as max. Max is 170 bar I've been told.

Hammer is the 13 gram. Came with the gun. But I have added a hammer spring spacer that some guys get with lighter hammers. The hammer spring spacer is about 1.4 mm thick, so that effectively adds 2.8 turns of the fine spring preload screw (equivalent of 2.8 power wheel numbers -- 0.5mm per wheel number. One wheel number is a preload change of 0.5mm. The spacer effectively adds a little weight to the hammer. I don't remember how much it weighs.

I replaced the sissy 52mm hammer spring that FX put in the gun with a Huma spring that I think is known as the Impact high power tuning spring. It also fits the Maverick.

I replaced the pellet probe with a Huma pin probe. The Huma pin probe sticks out a little into the magazine area when cocked. So I have to pull the cocking lever back all the way when inserting or removing the magazine. This is the 2nd Huma pin probe I've had (same probe model). I sanded the end of the first one off so it would not stick out into the magazine area, but I ended up losing about 2.5 FPE when I did that. So I tossed out the sanded down one and bought a new one and that is what I'm using.

grungy

 

[Member 32425]

I am late to this thread and I came without much/any knowledge of the problem with the said airgun.

However, have you contacted FX about this? I mean, it would seem likely that they have already heard of this problem and may have some options to address it.

Other than that, if there is a forum/sub-forum here or elsewhere dedicated to FX airguns, especially the higher caliber guns, that *might* be your best bet.

Even though I don't own any higher caliber airguns, I think I know the sound you are talking about. I think you mentioned that it is probably the joined plenums and I agree that may be where the resonance originates, but that resonance is carried to other parts of the airgun.

So, my suggestion is to do what you can to find/dampen the *source* of the resonance first and see if that helps before you go about wrapping the entire gun.

If dampening the plenums makes no difference, then maybe that is not the source of the resonance. So, start again. (smile)

Yeah, I know I am not much help and I know nothing about the gun you are using, but I do empathize with you as keeping my .177 airguns as quiet as possible is a quest and passion! Although I try to do it without a commercial moderator and sometimes use my own DIY slip on designs. (smile)

Hi BackStop. I don't think there is anything wrong with this gun other than I want it to be quieter than it is. I think this is just "normal" hammer ping/twang resounding through the entire system. Nothing unusual. FX would tell me to hire a phsychiatrist for the horse -- or back my FPE down from 109 to 100. The gun shoots great and I don't want to back off the power. I just want to get whatever high frequency ping that only 4 legged critters can hear to go away. When I started this thread I figured other people have had similar sound issues with not just this gun, but others as well. We'll see.
grungy

 

[BackStop]

Hi BackStop. I don't think there is anything wrong with this gun other than I want it to be quieter than it is. I think this is just "normal" hammer ping/twang resounding through the entire system. Nothing unusual. FX would tell me to hire a phsychiatrist for the horse -- or back my FPE down from 109 to 100. The gun shoots great and I don't want to back off the power. I just want to get whatever high frequency ping that only 4 legged critters can hear to go away. When I started this thread I figured other people have had similar sound issues with not just this gun, but others as well. We'll see.
grungy

I think you can *dampen* the noise, if not get completely rid of it. Of course when using a heavy HS and shooting at the upper end? of the power curve for a given gun, there may be only so much you can do.

All I can say is good luck and I wish I could get my idea of the sound you described out of my head! (chuckle)

Time to think of a Led Zeppelin tune (The Ocean) to drive it out... (grin)

This one usually works when I get an annoying song inside my head. (smile)

 

[Member 32425]

I think you can *dampen* the noise, if not get completely rid of it. Of course when using a heavy HS and shooting at the upper end? of the power curve for a given gun, there may be only so much you can do.

All I can say is good luck and I wish I could get my idea of the sound you described out of my head! (chuckle)

Time to think of a Led Zeppelin tune (The Ocean) to drive it out... (grin)

This one usually works when I get an annoying song inside my head. (smile)

BackStop, listening to The Ocean now. That helps a lot. Seriously. I haven't had to think about answers to questions and respond in rapid fire mode like this since I was a computer programmer. I kind of had a headache until Zep started playing.
As far as power curve is concerned, every tune for this gun I've come up with for different slug weights has always been on the lean side of the power curve, so giving up a bit of energy for the sake of accuracy and consistency and not wasting air. Didn't matter if we were shooting 49.5 nsa, 47.x nsa, 54.5 nsa, etc. and it didn't matter which barrel we used, 1:22 twist or 1:18 twist, this gun is just putting out some kind of ping that doesn't bother people, but does bother the horse. I'm assuming that other critters are bothered by it too, giving away my hunting position, but maybe this horse is just... different?
Anyway, I don't mind wrapping the gun barrel and stuff with something that works -- snipers do it. I just hope I find the right stuff to wrap it with without having to try 10 different things.
grungy

 

[BurntDog]

Hmm, how hard would it be for you to build shooting booth (just a place you sit/stand up range from the target) and use that sound proofing you spoke about used in studios? Nothing fancy just enough room for the shooter. Are those tiles pricey? I have seen people use different types of material in DIY videos.

 

[N2 Shooter]

Hi estarkey7.

I don't think anyone has experienced this except me and my shooting buddy. I'm just glad the horse's owner hasn't accused us of shooting AT his horse -- that has never happened and never will. We are both afraid that we might be wrongly accused of this every time the horse spooks from a ping sound 100 yards (or more) away.

I have an FX Maverick 30 caliber sniper (700mm barrel). The barrel I just now put in it is the 1:18 twist rate barrel so I can get better stabilization from heavier slugs (currently in process of tuning for nsa 54.5 grain slugs and I'll probably stick with this). The barrel that came with it is the 1:22 twist rate barrel that I used primarily with nsa 49.5 grain slugs.

1st reg 180 bar (set it a long time ago and it has probably settled down to 175-177 by now). 2nd reg 160 bar (set it a long time ago and really seems to like settling back down to 158). These are the original FX regulators that came on the gun. I know I'm pushing the 1st reg more than is specified as max. Max is 170 bar I've been told.

Hammer is the 13 gram. Came with the gun. But I have added a hammer spring spacer that some guys get with lighter hammers. The hammer spring spacer is about 1.4 mm thick, so that effectively adds 2.8 turns of the fine spring preload screw (equivalent of 2.8 power wheel numbers -- 0.5mm per wheel number. One wheel number is a preload change of 0.5mm. The spacer effectively adds a little weight to the hammer. I don't remember how much it weighs.

I replaced the sissy 52mm hammer spring that FX put in the gun with a Huma spring that I think is known as the Impact high power tuning spring. It also fits the Maverick.

I replaced the pellet probe with a Huma pin probe. The Huma pin probe sticks out a little into the magazine area when cocked. So I have to pull the cocking lever back all the way when inserting or removing the magazine. This is the 2nd Huma pin probe I've had (same probe model). I sanded the end of the first one off so it would not stick out into the magazine area, but I ended up losing about 2.5 FPE when I did that. So I tossed out the sanded down one and bought a new one and that is what I'm using.

grungy

I would try using the new Tungsten hammer weight for the Maverick. I believe you may be experiencing some resonance between the hammer weight and the spacer. Additionally, the higher density of the Tungsten hammer will dampen out any additional vibrations. Also, try the carbon fiber barrel stiffener which should slightly improve accuracy and should dampen any vibrations that may be happening between the shroud and the barrel liner.

 

[Member 32425]

I would try using the new Tungsten hammer weight for the Maverick. I believe you may be experiencing some resonance between the hammer weight and the spacer. Additionally, the higher density of the Tungsten hammer will dampen out any additional vibrations. Also, try the carbon fiber barrel stiffener which should slightly improve accuracy and should dampen any vibrations that may be happening between the shroud and the barrel liner.

Hi estarkey7. I think you could be right about the spacer between the hammer weight and the spring. It is definitely an extra part bouncing around in there that I don't need. I'm glad you mentioned that. It might just be that simple -- ditch the spacer. It could be making some high-pitched "overtones" as far as the sound goes. I'm going to do that. I know I can get enough preload without the spacer.
I do have the carbon fiber sleeve -- I forgot to mention it. Thanks.
grungy

 

[Patrick1]

Hi estarkey7. I think you could be right about the spacer between the hammer weight and the spring. It is definitely an extra part bouncing around in there that I don't need. I'm glad you mentioned that. It might just be that simple -- ditch the spacer. It could be making some high-pitched "overtones" as far as the sound goes. I'm going to do that. I know I can get enough preload without the spacer.
I do have the carbon fiber sleeve -- I forgot to mention it. Thanks.
grungy

I think he meant the carbon fiber barrel tensioning system, not just the sleeve over the barrel. I believe he is thinking the epoxy bound graphite fiber system would dampen the higher frequencies better than a metal shroud would. JMHO

 

[Member 32425]

Hmm, how hard would it be for you to build shooting booth (just a place you sit/stand up range from the target) and use that sound proofing you spoke about used in studios? Nothing fancy just enough room for the shooter. Are those tiles pricey? I have seen people use different types of material in DIY videos.

Hi BurntDog. Sorry I went off into wonderland with my audio studio rambling. I never did make a point with all of that. I could have, but it would have read like a 30 page thesis for a master's degree in audio engineering. Anyway, there is no plan to make a sound dampening booth to shoot from. My gun goes where I go and I just need to tame the excess pingy/twangy sound. The tricky part of this is that humans can't hear the sound that I need to quiet down -- so I just have to try different things with the gun until the horse can't hear it either. Like estarkey7 mentioned in an earlier post, it might be as simple as removing the unnecessary spacer between the hammer and the hammer spring. I'm going to do that first and see how it goes.
grungy

 

[Member 32425]

I think he meant the carbon fiber barrel tensioning system, not just the sleeve over the barrel. I believe he is thinking the epoxy bound graphite fiber system would dampen the higher frequencies better than a metal shroud would. JMHO

Oh. Yeah, I just have the sleeve that fits beween the liner and the barrel housing. I didn't know the tensioning system had all the bugs worked out, but it's been a long time since I've looked at that. I'll check it out. Thanks Patrick1.
grungy

 

[N2 Shooter]

Hi BurntDog. Sorry I went off into wonderland with my audio studio rambling. I never did make a point with all of that. I could have, but it would have read like a 30 page thesis for a master's degree in audio engineering. Anyway, there is no plan to make a sound dampening booth to shoot from. My gun goes where I go and I just need to tame the excess pingy/twangy sound. The tricky part of this is that humans can't hear the sound that I need to quiet down -- so I just have to try different things with the gun until the horse can't hear it either. Like estarkey7 mentioned in an earlier post, it might be as simple as removing the unnecessary spacer between the hammer and the hammer spring. I'm going to do that first and see how it goes.
grungy

As an engineer, I often transform things from the time domain into the frequency domain for further analysis. If you watch my pest control video in this link, when the video is slowed down, you hear the complexity of the high pitched squeal when the plenum fills back up. This may also be a source of noise that we cannot hear that may be scaring the horses.

 

[Member 32425]

As an engineer, I often transform things from the time domain into the frequency domain for further analysis. If you watch my pest control video in this link, when the video is slowed down, you hear the complexity of the high pitched squeal when the plenum fills back up. This may also be a source of noise that we cannot hear that may be scaring the horses.

Interesting thought. That would never have occured to me had you not mentioned it. Mostly it would not have come to mind just because filling the plenum is a relatively quiet (to humans) process as opposed to a hammer hitting a valve. And the horse is 100 and more yards away. But dog whistles don't need to be smacked with hammer to call a dog that is farther away than the horse. Dang it. I never wished I was a horse before. But now I wish I could be one for just a little while when my buddy is shooting.
grungy

 

[OldSpook]

You know, just food for consideration, someone else MAY have shot that horse with a BB gun or an airgun at some time. That would make him very sensitive to that sound.

 

[Member 32425]

You know, just food for consideration, someone else MAY have shot that horse with a BB gun or an airgun at some time. That would make him very sensitive to that sound.

Hi OldSpook. That is entirely possible. It would explain a lot.
grungy

 

[Airgun-hobbyist]

@grungy The high pitched pinging sound that you are experiencing is coming from the large penum chamber when the valve opens, all due to the gun getting tuned for high power. The simple fix is to place anything in the plenum chamber that will break up and stop the air's reverberating ping and not effect the plenum volume (by too much), or air flow. As a member said previously, don't use a bottle brush for a permanent solution as the bristles can and do break. I have used a piece of plastic corigated loom tubing in non-regulated airguns where the ping is way more pronounced. Hardware stores carry different diameters of wire loom tubing in the electrical section. (Google "Gardner Bender Black Polyethylene Flex Tube" ) This stuff also works great in the FX's hollow moderators.

 

[Member 32425]

@grungy The high pitched pinging sound that you are experiencing is coming from the large penum chamber when the valve opens, all due to the gun getting tuned for high power. The simple fix is to place anything in the plenum chamber that will break up and stop the air's reverberating ping and not effect the plenum volume (by too much), or air flow. As a member said previously, don't use a bottle brush for a permanent solution as the bristles can and do break. I have used a piece of plastic corigated loom tubing in non-regulated airguns where the ping is way more pronounced. Hardware stores carry different diameters of wire loom tubing in the electrical section. (Google "Gardner Bender Black Polyethylene Flex Tube" ) This stuff also works great in the FX's hollow moderators.

Thanks airgun-hobbyist. The thought of me disassembling (spelling?) an FX Maverick in order to stuff sound-absorbing material into either of the two plenums would be a huge chore for me -- a nightmare. I have yet to fully take this gun apart and put it back together again. Eventually I will have to learn to break it down and re-assemble it, but for now that's not going to happen. However, I have wondered how much quieter I could make my Maverick by stuffing the barrel shroud/moderator with something that would not snag on the barrel housing when removing and replacing the shroud. My initial thought was to stick closed-cell sticky-back foam or something on the outside of the plenums and shroud and wherever would be easy to get to.

Plain white sticky-back closed cell foam can be gotten cheap (commonly used for door and window weather proofing). It would look ugly and might come off easily, but then I found that camo printed duct tape is also cheap and wraping that around the closed cell foam might really quiet things down a bit and look kind of cool as well as block direct sunlight from heating up the black anodized aluminum and would hold the closed cell foam on.

Now that I'm on a bit of a roll, I found out that the horse that gets spooked so easily is also spooked by lesser powerful airguns -- specifically an Air Ventury Avenger 25 cal shooting NSA slugs at max power for that gun. I did not know this until a few days ago when my buddy who really does the shooting told me this. I thought it was only the powered-up Maverick that spooked the horse, but now I know that is not the case.

I'm really thinking that Oldspook's guess is right. I'm thinking that the horse in question has been shot with pellet or BB guns and is just traumatized and has really good hearing. Of course neither I nor my buddy did that -- maybe kids when no one was looking. We'll never know.

Anyway, thanks for the idea of stuffing the bell-like chambers with flex tube. Sounds like a good idea for the shroud.

grungy

 

[OldSpook]

BEFORE and after you are done shooting give the horse a visit, a pet, and if the owner allows a treat. Should clear things up in two or three visits. If he won't be calm for you just set the treat on a fence post, talk nice to him and leave quietly. They are like big dogs and will come around quickly.

 

[pnwairgunner]

It is just as likely that your moderator shifts the sound emitted from the airgun to a higher frequency than is noticeable to humans but still within the hearing range of horses. Unless you are hunting horses this may not even be an issue.
Also the sound of a projectile flying through the air is very audible to animals and people alike. With an ear that is three to four times the size of a human ear, horses can gather a lot more sound waves than animals with smaller ears. Cup your hands around your own ears to see the difference a larger ear makes on gathering sound.
Horses can hear low to very high frequency sound, in the range of 14 Hz to 25 kHz (human range = 20 Hz to 20 kHz).

 

[AmosBurton]

I'm not proposing to give up on making the gun quieter, heck I just tried making my moderator quieter....
I would try training the horse to relate that sound with food.
You show up and give it a carrot or apple. Shoot some, give it another mid shooting session. Shoot some more and another carrot before you leave.
I bet after a while the sound of shooting will bring the horse to you.

 

[qball]

You know, just the other day I tried to sneak out after work and get some squirrel hunting in. It was a lost cause from the beginning because I got to public lands in the sticks around 6pm, so I had around 25 min at best. At the end of my walk through the woods, I got back to my SUV and I shot the round I had chambered into the mud around 20 feet in front of me. Even with my DonnyFL Ronin on my Maverick VP .30cal, the echo that I got back sounded like someone was shooting a .17HMR at me from 300 yards away. I was so convincing I even ducked!

I'm not sure if this was due to the round hitting the mud with the FX Hybrid Slugs or just because I was way out here in the sticks, but it was just another example of you never really know how loud your gun is until you go downrange while someone else is shooting it.

View attachment 300457

Couple of possible reasons, first is if your are shooting super sonic which is unlikely and second is the loud pop from the FX hybrid hitting the mud. That slug has huge cavity and opens into a disk so the crack is probably the air inside got compressed and escaped at super sonic speed like a bull whip. Try shooting it into dry dirt, pretty sure the crack won’t show up.

As far as the mechanics noise goes, it is very hard if not impossible to quiet it down. Only sure way is to reduce power so the hammer doesn’t hit the valve that hard. Maybe a heavy box encase the whole gun but how do your shoot it?

Due to the power of new Crown MK2 I have no way to quiet down the hammer noise either, not as bad but still not good. My Dreamline on the other hand is spooky quiet, just a subtle clack. You can only get so quiet at certain power level, anyone knows a mouse fart quiet 50BMG?