What is the Barrel Length of a Silencer for the ATF Form 1, ATF Form 4, or ATF Form 5?
Whether you are applying for a tax stamp to build your own silencer using the ATF eForm 1/ATF Form 1 or you are transferring a silencer using the ATF Form 4/ATF Form 5, you are still required to complete the application to apply for that tax stamp. Box 4e of the aforementioned forms will ask what the barrel length of the silencer is. This is some what of a misnomer in the sense that the silencer doesn't actually have a barrel length. The value that you will use for Box 4e is simply "N/A." From there you can continue to fill out your application. Please see the below examples of the ATF Form 1, ATF Form 4, and the ATF Form 5 where Box 4e is filled out correctly.
ATF Form 1
ATF Form 4
ATF Form 5