I believe that the large section was filled with shoelace eyelets (aluminum) around about a 1" ported "barrel".

OK I deserve the response I got.
Thank you all. My question has been answered. End of topic, unless some one else wants to jump in.

Is it possible to apply for a form 1 silencer build for a existing unregistered silencer?

Thanks all, for all of the replies.I think I will play it safe and wait for my form 1 and tax stamp before doing anything.

Thank you very much for the info.
I very much wanted to do this build for many years, but I lived in The Peoples Republic of New Jersey.(where they just made it a felony to posses a unregistered BB gun!
I have since moved to West Virginia a state friendly to gun owners.

Hello: This is my first post on this site. I want to build an integral suppressor on an Hi-Standard HD Military. Under length on the form 1 is the length of the outer tube what needs to be entered? Second question. once completed (and with form 1 and tax stamp) would I have a problem transporting it...