Opinion: Why The Reverse Paradox Tube is NOT a Firearms Silencer In the previous article about the reverse paradox tube, there was a comment that the BATFE might consider the tube to be a silencer.Legally, the reverse paradox tube is not a silencer. The law is clear, and there is considerable precedent as to why this is so.The definition of a silencer, in the law, is in 18 U.S.C. § 921(a)(3): (24)  The terms “firearm silencer” and “firearm muffler” mean any device for silencing, muffling, or diminishing the report of a portable firearm, including any combination of parts, designed or...