Sorry, more OT legal junk:

Some folks here have commented alot using a Form 1 to "make" a short rifle or shotgun. Many folks may not be aware that there is another option that does not involve placing your name and city, state info on the gun.

You can send the gun off to any licensed manufacturer (like Vector Arms in Utah, etc.) who can "make" it tax free on their license using a Form 2. In some cases, this is as simple as putting a stock on your pistol, etc. They mark it with their name according to law which is generally better if you resell the gun down the line because your name is not on it, theirs is.

They can then transfer it back to you directly across state lines on a tax-paid and approved Form 4 even though you do not have a FFL. The ATF allows you to bypass the usual transfer dealer in this case because you owned the original gun to start with. You must provide a note to that effect and include it with the form 4. I would also include any proof of original ownership. This shortcut doesn't save you on taxes (unless the item is made into an AOW), but it will save time and transfer dealer fees.