Each time you buy a new NFA firearm (such as a silencer, short-barreled rifle, or fully-automatic rifle) from a Class 3 dealer, the dealer needs a complete copy of your NFA gun trust, since it is included as part of the ATF Form 4 application that the dealer sends to the ATF. Similarly, each time you want to register to manufacture an NFA firearm, the ATF needs a complete copy of your NFA gun trust, since it is included as part of the ATF Form 1 application that you send to the ATF.