Improving your silencer

[Guest buster321c]

Points to note about silencers on springers:

 

* You will never make the gun fire silently. The action of the gun i.e. the moving piston and the spring make a lot of noise.

* When you fire a rifle, you have your head on the stock and the noise is transmitted through the wood and the metal directly to your ear.

* The easiest way to hear the effect of a silencer on a springer is to have somebody else fire it while you stand a metre or so to one side. Hint. Don't get shot!

 

General points about silencers, the smaller the hole in the baffle the better and the bigger the silencer better. So ideally a silencer for a 0.177 should have smaller diameter hole in the baffle than a silencer for a 0.22.

 

There is a practical limitation to this. The pellet must not clip the baffles so tolerances are critical. A 0.22 pellet passing through a 7-mm hole will at best have 0.75 mm on each side of it. When you consider that the final baffle might be some distance from the end of the barrel it become obvious how important it is to keep everything lined up.

 

Fortunately making baffles with a hole exactly in the middle is easy if you do it the right way.

 

Here is how its done.

(This procedure should work when making baffles to go into a parallel-sided tube.)

 

First get some washers that are just a bit over size. For this silencer get some 32-mm washers from B&Q. The ID (the hole in the middle) was 5mm.

 

Safety Note - Use safety glasses or goggles when filing or grinding the washer. Use all tools with respect and care.

 

* Get a 5mm-machine screw and two nuts. A machine screw is just a bolt with a countersink head. Use a screw to match the internal diameter of whatever washer you are using.

* Drop the washer onto the screw and run a nut down on top of it. This will centralise the washer with respect to the screw by pushing it onto the cone of the countersink. Using a screwdriver and a spanner tighten the nut down onto the washer.

* Run the second nut down onto the first and tighten it. This will act as a lock nut.

* This brings us to the only power tool you actually need. Fit the screw into the chuck of a power drill. It is better if you use a shorter screw than the one in the picture so that the chuck grips the nuts rather than the screw thread.

* With the drill running put a file or stone onto the side of the washer. I mounted mine in a bench drill and used a file. Start reducing the diameter of the washer but stop frequently to test it for size.

 

 

 

Screw and washer.

 

The washer is the correct size when it will slide smoothly into the empty silencer tube. The importance of this fit cannot be overstated. It must neither be loose nor must it jam up.

 

Centring the hole.

It's easier if you can use a bench (press) drill.

 

Put the washer flat in the vice on the drill table and lower the drill into the existing hole in the washer. I used a 7-mm drill. Pressing down gently I rotated the drill by hand in reverse i.e. not the direction of cut. This centralised the washer under the drill bit; then I clamped the vice and washer onto the drill table and drilled the hole.

 

If you do not have a bench drill just drill through; it's not quite as good, but you should be OK.

 

I used just 3 baffles , enough to produce 4 chambers. It is important for acoustic reasons that the chambers be of different sizes and that none of them be even fractions (half, quarter and so on) of the length of other chambers.

 

Spacers.

You have to have some thing to separate the baffles. I used plastic waste pipe, it's inexpensive, easy to get and easy to work with.

 

Cut a number of rings from the pipe and make them of varying size. Mine range from about 25 mm down. To reduce the diameter of the tube I cut sections out of it length ways and just squashed it up and pushed it into the silencer tube. Obviously the size of the section you cut out depends on the diameter of the poly-pipe and the diameter of the silencer tube.

 

 

 

 

Poly-pipe ring with section cut out.

 

You don't have to use poly-pipe; lots of other tubular things can be use including springs. Something to note is that the spacer should be cut at 90 degrees (cut square) to the axes of the tube. I have had success using a mitre box but also by marking up carefully and cutting free hand.

 

How to mark up.

Get your poly-pipe and wind a piece of A4 paper around it making sure that the edge of the paper is flush with itself all the way around the tube. This is much easier to do than to explain, if you try it you will see what I am talking about. Mark the tube at the edge of the paper with a spirit based marker.

 

 

Cutting.

Almost any saw will do the job. Just cut carefully along the line and scrape off any loose bits.

 

Arranging the baffles and spacers.

This is a black art and there is nothing I can suggest but trial and error, as it depends on the gun. So saying, I use a larger (counting from the muzzle) first chamber, then a smaller second chamber and a small (about 10 mm) 3rd and medium 4th chamber. No two chambers are the same size.

 

Acoustic dampers - felt and so on.

Felt is the most common but "Green Kitchen Scourers" have also been used. B&Q do some self-adhesive felt for the bottom of chair legs that is very suitable. I just cut some felt rings and glued them onto the baffles with contact adhesive ( Evo-Stick).

 

Putting it together.

To keep things tight, work from the end furthest away from the silencer's muzzle. Push in a spacer then a baffle then a spacer and so on. The end cap should push the last spacer into the tube. Doing it this way makes sure that there are no gaps and nothing can rattle.

 

Checking the line up.

Break the gun and look down the barrel from the breech end.

 

Safety Note - If you have cocked the gun, keep a firm grip on the barrel to prevent its accidentally snapping shut.

 

You should see two perfectly concentric circles. One formed by the barrel at the breech and the other by the muzzle. If you see something that is not perfectly circular you will need to check the line up of the silencer tube. When it is not OK and the problem persists, rotate the individual baffles within the tube to see if you can get an acceptable line up. If you cannot manage that then either make the holes in the baffles bigger or buy a silencer!

 

To round it up.

I have managed, for less than £3, to reduce the noise made by it by a considerable amount and to give it that "Quality Gun" sound. It is now noticeably quieter that most other spring guns, that's assuming that someone else is firing it. Remember what I said about the stock conducting sound?

 

 

 

Disclaimers.

If you wish to use any of this information you do so entirely at your own risk.

 

 

Shamelessly copied from another site , atb Buster

Thanks to Ora