This is old but new to me and searching the forum I didn't find anything on this. The Weapons Man blog, where I initially came across it has the letters on the subject from the ATF. He implies that they backed off of this position but I haven't found verification of that and the letter about it suggests it might still be a potential problem: http://weaponsman.com/?p=25748#more-25748But that’s not all. The original letter included a question about the owner of a legally owned silencer having a reserve of such pads. In case, you know, they needed to clean something. According to the ATF that would be considered a “stockpile” and considered an illegal act.
The letter says it's an offense if someone "accumulates or otherwise intends".....and that replacing the sound adsorbing material in a legal suppressor is the same as manufacturing one. Note, the letter also refers to bottles, rubber washers, copper pads, and steel wool. I don't have a suppressor now but I might want one some day....anyone have more recent info on this?