Back seven or eight years ago, DB got rid of their threaded barrels and silencers. I regret to say that I passed on an offer to obtain a barrel and silencer, as I figured the gun then would not fit in a pants pocket. I was lucky enough to get a ported barrel. I don't think DB still sells them anymore.
Please understand that I have not been around the DB forum for a few years so that is old news.
Best, Bill