text: how to build a suppresor?   supressors or silencers, are legal in many areas of the us today (arizona, being one). construction can be rather simple.  the lengthy answer posted above describes what one is, but does little to help you build one. depending on the power of your cartridge, you should attempt to have an outer tube of roughly 3 times the outer diameter of the barrell of the gun. washers drilled to .05 inch larger than the bullet  (this must be precisely centered) welded to either end.  internally you may use several methods 1. the close stacked method.  this uses a series of hard and soft spacers, typically made of steel washers and 3m green scrubbing pad-type material (the kind used for scouring pots and pads) packed alternating materials until the tube is full. a nut is centered and welded onto one of the end washers. this is a heavy and not completely silent supressor, but it is cheap and easy to build the second type follows current auto and motorcycle muffler design. again starting with an outer tube and end washers correctly drilled. inside there is a steel screen or perforated sheet of steel rolled in a diameter slightly larger than the bullet, so as not to contact the bullet.  the space between the screen and the outer tube is stuffed with either fiberglass or steel wool.  if using steel wool, it is recommended to use various grades to help absorb a wider range of frequencies. this type of supressor is musch lighter and efficient and lasts a very long time.  the drawback is that it takes a much more skilled hand to fabricate.  enjoy!