Re: Form 1 suppressor .. Length ??
Yes. Some people including myself put N/A in the silencer length, but the ATF has been sending them back more often lately with instructions to include an actual length.
It is important not to make the silencer longer than the listed length, but making it a bit shorter is ok. This is because the ATF does not allow lengthening the tube when repaired, but making it a bit shorter is ok.
Ranb