This is more of a just wonder then having to know, but I remember from the movie 'The Transporter' the Chinese Business Man, has a 686 with a added on compensator. You can find it at this link.
Is there a company that makes one? I been itching to make a 'Custom' gun for myself, as I have access to a bunch of S&W revolvers for sale. Just thought it would be a good item from some friendly discussion.
Add on Compensator
Linear Mode
