This is a remix of the parts base on them fitting into a 1-1/2"X12" STRAINER TAILPIECE. See the images for a reference. It is a thin wall pvc pipe that this was made to fit. I sized the pieces down to fit better. Either way you may have to scale your model up or down to fit. I have included a small ring that is the size of the end caps. You can print this as it should be a quick print to see what scaling you need. You want it to be extremely tight. Depending on the quality of the tailpiece you may find that it is not completely even on the interior of the pipe.

Next I changed one of the baffles with holes and a little bit of twist to create more air friction.

You can use the tailpiece as a single 12" silencer OR as I did cut it in two and have two. I did this to play with the configurations to see if either are better. In addition I also played with cutting foam and placing in between the baffles. If nothing else having the foam in there helped keep the baffles tight between each other. If you make the foam make sure you cut the middle hole with plenty of space. You do not want a pellet or bb hitting the foam. I wanted tight tolerances the first time and it blew apart after a couple shots because one round caught the foam and then the next ejected the entire front couple of baffles.

Note this is NOT for a fire arm! Airsoft/BB only! Both for the physical properties as well as legal. It does work for reducing the crack on the muzzle sound.

In addition anytime you take the silencer off you probably will affect your POI. It did not seem to affect my accuracy but definitely where I was hitting ever so slightly.

I tested on a Air Venturi Avenger with a 1/2-20 threading.