I'm considering starting a Form 1 to create an SBR built on the AR platform. I'm not sure I understand the process. If someone who has done this could clarify a few things, I would appreciate it:
1) Form 1 requires you write down the overall length and barrel length. I don't have all of the parts as it would be illegal to assemble anything, at this point. How do I measure / guestimate the overall length? Also, I've read that you can put a longer barrel on, but can't go shorter than what you write on your Form 1, is that true?
2) I need to purchase a lower receiver for this project so I can put a serial number on the Form 1, right? I need the lower before I fill out the Form 1, right?
3) What's all this business about using it as a "pistol" until the stamp comes back? Do I have to buy the lower in a special way for it to be considered a pistol? Can you just buy a plain-ol' lower and a pistol buffer tube and call it good?
4) I've seen a thread asking about NFA engraving before, but I can't find it. Anyone have a good shop that can engrave to NFA standards and re-anodize that part of the lower?
Thanks in advance for departing your wisdom.