An airgun silencer, model supplied for 22 calibre, with an expansion chamber and K-type baffles that prints without support. Particularly useful for silencing CO2 and pneumatic airguns, designed for the Crosman 2250 “Ratcatcher.” Firearms will just blow it to bits and may present multiple hazards, so don't do that.

The silencer, technically a moderator, clamps on to the 11mm barrel with a 25mm M4 screw and nut. 70mm of the barrel goes inside the silencer, and the part behind the muzzle is used as an expansion chamber to give the gas somewhere to go rather than straight out the front.

Printing

Print without support, a minimum of 4 layers and 30% infill, muzzle end down. A raft is highly recommended as the model is tall and thin.

Installation & Use

Look down the (unconnected) silencer and check that the hole is clear down the middle. Ensure your airgun is unloaded, because while fitting the silencer there is a good chance you'll end up accidentally pointing it at your face and I do not want to be responsible for any - very quiet - accidents. Slide the silencer over the barrel, and keep pushing it firmly in until it reaches a firm stop about 60mm deep. Insert screw and nut, tighten screw to firmly grip the barrel. Fire test shots in a safe environment to ensure your accuracy is unaffected and your print is structurally sound.

With air rifles such as the 2250 you will still notice noise. This is because the rifle's firing mechanism is very clunky, consisting of a big lump of flying metal coming to a rapid stop, and a big, twangy spring.

Do not use it with extra long airgun pellets as they may tumble inside the silencer - long projectiles are not really suitable for CO2 airguns anyway and lack accuracy at low velocities.  Do not fire pellets backwards through it either. Ask me how I know.

Modification

The OpenSCAD files allow you to change the calibre, barrel diameter, the length of barrel that telescopes inside the silencer, and the number of chambers in the silencer. Do not modify the design for very large diameters, or you won't see your sights!

If you don't do OpenSCAD, you can haul the design into TinkerCAD and modify it manually from there.

If you like this or find it useful, you could buy me a coffee on https://ko-fi.com/viksworkshop

Notes:

This works perfectly well in PLA. Do not use low power airguns for pest control, particularly pistols conforming to EU regulations.