Effective Removable Suppressor

Eraser & Freezy had asked me about some suppressors I have been trotting out, and I have a design I'd like to share. It's removable, effective and adaptable. It uses a spent caulk tube for the main body. The plunger from inside the caulk tube is used as the endcap. The ports in the barrel can be fiddly and will require some patience, and perhaps some trial and error. The method I show uses simple tools and has a high success rate.

Here's the tools we'll use. Pretty standard except for that odd shaped, dark dremel bit. It's a very fine abrasive polishing bit that is similar to a rough pencil eraser. The weird pigtail looking piece of wire is wrapped around a 30watt soldering iron and is used to locate and start the barrel ports. The drill bit is 1/8".



Here's our materials. An empty caulk tube (or quickcrete for yellow!), some cottony material (I used a ripped up aquarium filter), some fbr blanks (I used pool noodle material) and a few rubber bands.



Fill the caulk tube with hot water. Clean the inside surface with a toothbrush to remove the caulk residue and free the plunger in the end of the tube. After it sits a few minutes, empty the water & push on the plunger (through the nozzle hole) with a blunt instrument till it falls out. Clean out the remaining caulk. Cut the nozzle off the tube. Add a starter hole to the middle of the plunger with the small burr-style dremel bit. Enlarge the hole there and at the nozzle end with your drum sander bits until they fit tightly over your barrel like so:



Now we'll port the barrel. Make sure that the first hole will wind up inside the caulk tube when it is fitted on the barrel. I like having the muzzle stick out a bit past the suppressor so I can really push the barrel into the coupler.

Here's the soldering iron with my weird, makeshift tool attached. Let the iron heat up for a few minutes. If the wire slips off the iron, let it heat up a minute before you try to make another hole. It should take about 10 seconds to burn each hole.



Here's where I placed the first port. The mark shows the inside edge of the suppressor. The hole should wind up a ways back from this to improve airflow.



I then marked a spot directly across from this hole with a mechanical pencil.



Now we can easily drill though both holes. Here I show the process repeated. This "cross" of four 1/8" holes will allow us to eyeball the rest, making construction smoother. The rest of the holes will be kept smaller.



Continue burning holes in the barrel in 2 lines, for a total of 16 holes. Start the second line of holes behind your original to ensure that the ports stay inside the main body.



Now we'll bring the ports to their final shape and smooth the interior of the barrel. I will start by running the burr dremel bit along the inside edges of the holes at an angle as pictured. I use my thumb as a brake on the collet of my janky dremel and go at a low speed to avoid scratching the interior of the barrel.



Now to concentrate on smoothing out the inside of the barrel port area. You can see that I have worked on the first line of holes. I will use my Stanley knife to carefully remove the debris that I can. I will go over any stubborn areas with the burr bit again. After that there are usually a few small bits of flash left. I'll use that red conical polishing bit (by hand) to remove that. The dark rubber abrasive bit is used at the very end to hone up the whole area (again, by hand). It is all important that this area be completely free of any burrs or flash. If there is any effect to accuracy at all to your blaster the answer will likely be to check this area.



I chamfered the outside of the ports and sanded the whole area.



I added 4 holes to the endcap like so:



We can assemble it now. Push the endcap on all the way. Wrap the cottony material around the barrel and secure it with rubber bands.



Insert the barrel into the main body. Stuff some blanks in the space left. I used 8.



Push the endcap into the main body and feed the barrel through, stopping when it's flush like so:



Done! Shown on my BBB, since it was nearby. This is for Spring and Air powered blasters.



I've tweaked this design 4 or 5 times and this iteration is particularly effective. Some sophistication can be added. A 2 stage system can be implemented by adding another plunger (with perforations) in the middle of the main body. 2 caulk tubes can be linked to provide more volume. Some experimentation with the damping materials can likely yield benefits. Variables like volume, location & diameter of ports, length of the barrel between the port area and the muzzle, etc., can be played with. There are some improvements that can be done to make the suppressor easier to move from blaster to blaster and be more secure. If I manage to stay out of Guantanamo I will update this thread.

This device attempts to dampen the sound of any "pop" accompanying a dart being fired. It re-reoutes some of the air that escapes the muzzle along with the dart upon firing. The space allocated to capture the incoming air uses baffling and pressure to change the sound profile of the "muzzle report" of the blaster. It is surprisingly effective. It effectively silences the report of many blasters it's fitted to. The noise floor is lowered to the point that you will have to go in and silence the internals of your blaster thoroughly. It is effective on air powered blasters and reduces the report about 40% on the loudest of mine. Accuracy is unaffected if it's built carefully.


Testing & Basic Tuning :

1) If you seal the muzzle with your finger and blow through the breech end of the barrel there should be an easy, unrestricted flow out the ports. If there is sputtering or any resistance, and your ports are all clean and evenly shaped, make the holes larger.

2) The 4 small holes in the endcap serve a purpose. There needs to be steady airflow, but with some noticeable resistance here. Assemble the main body and endcap without the barrel. Use your finger to seal up the hole the barrel would fit through and blow through the muzzle end of the main body.

3) The packing (aquarium filter material and blanks) inside the main body needs to have some "bite" on the air flowing through it. Again we can test it by just blowing through it, checking the resistance and adjusting as necessary.


Here's some mechanical silencing methods I have had success with.

They are: carefully laid out draw extensions, self stick linoleum floor tiles as damping material, gel(silicone?) shoe insert material incorporated into the plunger padding, elastic sports wrap around the outside, neoprene and foam wraps, and quickcrete around the plunger tube (as bedding material, think tinfoil for method.

One method I have tried for gel & or rubber plunger padding is to sew & glue a slice between 2 layers of craft foam and cut it down with a stanley knife to shape. It helps to thin down the craft foam & or the plunger itself (when possible) to keep the thickness down. Craft foam compresses too much anyway. I have tried using a smaller disc of rubber cell phone cover material in the center of many setups to create a more conical shape. I haven't been able to get rubber or silicone stuff to glue up well, hence the odd methods.


Opinion:

There's some discussion as to whether this is worthwhile on a springer. I apply a simple mantra to these things. If I can do 20 things that will each give me a 1% advantage I will do those 20 things. This is one thing that you can do to help. This may not work on all blasters, in all situations, but it can be useful.


Quick test video. I need to take more shots and get the sound right. But the cat herding & testing was tiring, so, later. It shows a double with no padding (2 & 2 1/2" barrels). It also shows a quiet nano with gel plunger padding, self stick tile damping & a teeny suppressor w 2 1/2" "active" length barrel. Both with taggers. Quiet shot at 14 seconds.

They use this in alot of air gun designs as well I'm pretty sure.

I honestly cannot see any logical reason why this would make any nerf gun quieter.

No noise comes from the 'speed' (or gas discharge or whatever) of the projectile exiting the muzzle...

It does look cool though.

Someone responded with a better explanation than I can provide:

torukmakto4
"For nerf, all you have to do is remove the pressure from the bore near the muzzle just before the projectile exits, and vent that pressure into a muffler."


I do get some blasters that give me quite a "pop" when fired.

You do get quite a "pop" out of a singled titan. Not that it's ever been an issue for me personally, but I like this, so I'll definitely be giving it a try.

Nice work mate.

Cheers,

I like the idea, particularly for aesthetic reasons, but as we know, with 90% of nerf guns if not all suffer from reduced ranges when adding a barrel extension, weighing up the options of having a reduced range compared to a slightly quieter gun, to me isn't worth the trade off.

Out of interest, what are the ranges like when using the suppressor? if it isn't mush of a difference, I'm willing to knock one up for myself to see how it fairs with a few of my blasters.

[G] wrote:I like the idea, particularly for aesthetic reasons, but as we know, with 90% of nerf guns if not all suffer from reduced ranges when adding a barrel extension, weighing up the options of having a reduced range compared to a slightly quieter gun, to me isn't worth the trade off.

Out of interest, what are the ranges like when using the suppressor? if it isn't mush of a difference, I'm willing to knock one up for myself to see how it fairs with a few of my blasters.

Actually, most air blaster's perform better with longer barrels. It's usually springer's that suffer reduced ranges.

From my experience - Titan, 4B, BBUMB tanks work well with barrels around 2 ft long. Plenty of length to add a suppressor if you felt the need to.

Cheers,

Oh my mistake, I think I have been awake for too long, I was trying to comprehend why no one had addressed the issue, now it all makes sense.

I have not built 2 identical length barrels to test this out with yet. One problem is that it's a bit of an apples and oranges/catch 22 situation. One ported barrel will not perform the same as an identical length solid one. And just going by the usable length doesn't factor in the ports. But my impression is that the power lost to the ports is negligible. Don't forget that it's nearly the end of the barrel that's vented. The dart should be very nearly done accelerating. If you start your ports a little before optimum barrel length for your blaster your ranges should be very close to normal.

Thats very good nice mod. XD

This seems to be a touchy thing when applied to springers. I felt obligated to bring in some mechanical silencing methods I have had success with.

They are: carefully laid out draw extensions, self stick linoleum floor tiles as damping material, gel(silicone?) shoe insert material incorporated into the plunger padding, elastic sports wrap around the outside, neoprene and foam wraps, and quickcrete around the plunger tube (as bedding material, think tinfoil for method) as mechanical methods of dealing with sound.

One method I have tried for gel & or rubber plunger padding is to sew & glue a slice between 2 layers of craft foam and cut it down with a stanley knife to shape. It helps to thin down the craft foam & or the plunger itself (when possible) to keep the thickness down. Craft foam compresses too much anyway. I have tried using a smaller disc of rubber cell phone cover material in the center of many setups to create a more conical shape. I haven't been able to get rubber or silicone stuff to glue up well, hence the odd methods.

A supressor is a novel idea, I've looked into it once or twice. However, the only thing I may be able to see this useful on is airguns.
In a springer, a 90% of the noise is created by mechanical methods, aka: the plunger slammin against the end of the plunger tube. A supressor of this design is only dealing with that other 10%, which is air expelled out the front of the barrel.
However, I do like this idea in airguns, in which the situation is quite the opposite. 90% of the sound is created by air expanding from behind the dart at a hell of a rate, which is where the supressor buffers this "crack" or "pop".
And by no means am I bad mouthing this design, I love it! Will definitely give it a shot soon.
Good job!

You are right that this only deals with a percentage of the problem. The suppressor plays an integral part though.

I would have thought that a springer was impossible to silence enough to be useful until I tried it (after a few tries). I built a near silent jolt today. A nano which has the barrel moved to an inline arrangement. It is a little louder than normal usually. It's so quiet now that I estimate that you'd lose the ability to tell where a shot was fired from at 20'. I lost 2-3' in range. I still have to try half the mechanical silencing methods I mentioned on it.

I'm going to do some blaster specific write ups as an accompaniment to this and will post video and audio test data. I am happy that people are interested in this neglected area of blaster mods.

The wrap won't cover up as much when it's done. It needs orange paint of course. I don't think this one has hit Aus yet but believe me, it can be quite a loud blaster. Not for it's size.. Just plain old loud.



Quick test video. I need to take more shots and get the sound right. But the cat herding was tiring so, tommorow. It shows a double with no padding (2 & 2 1/2" barrels). It also shows a quiet nano with gel plunger padding, self stick tile damping & a teeny suppressor w 2 1/2" "active" length barrel. Both with taggers. Quiet shot at 14 seconds.