Ok, so you guys know I want to make a mini-AR.  Do I have to wait until I find a legal pre-ban, and get the approved paperwork before I can start buying my needed parts?  Or would they be illegal to own until I have the pre-ban lower and form 1 back from the ATF?

Parts I'll need:

Telescoping stock
11.5" pre-ban upper

So, would/could I be busted for merely owning these parts, or would I be ok as long as I don't have the rest of the needed parts all together in a case (as an example.)  

By the way, I do own a complete post-ban rifle, if that changes anything.

Since you already have a complete rifle in the house (pre- or post-ban would not matter in the case of a short barrel), you'd be better off not having a short upper in the house until you get your Form 1 back approved.

Without the Form 1, you'd be in a position of having no legal way to configure the parts in your possession, and one very illegal way (putting the short upper on your existing rifle) - which could make a case of 'constructive possession' of parts to make an unregistered short-barrel rifle.

While the chances of you actually getting discovered/investigated, much less prosecuted and convicted for the constructive possession are probably negligibly slim, why tempt fate?  

You're looking at a 3-5 month wait just to get your approved Form 1 back for the SBR, so tacking another week on for delivery of the short upper after your Form's back shouldn't be that big a deal.

When you get the Form 1 back, order the short upper, and you can use the time waiting for it to arrive to engrave your name, city and state on the lower.  When the upper arrives, you install it and you're done.

you could probably round up the parts and store them at your mom's house, or a friends.

FWIW it's called a Commando.  Mini AR sounds GAY.  just my Opinion.

good luck.

Thanks, Markm, for the information.  I like the term "commando" much better as well.  

Thanks all for the "constructive possession" information.