Forgive me if this has been covewred before, but I did do a search and did not find anything on my question.

If one goes throught the legal process to register a AR15 (pre-ban) as a SBR, would it be possible to change at random a .556 short barrel upper receiver and a short barrel 9MM? I assume the lower is registered, but, does the paperwork include a description of the caliber and barrel length? If I had to notify the ATF everytime I wanted to switch, then I would not be interested. If it's the lower receiver that has the SBR status and uppers could be changed, then it might be something worth thinking about.

Thanks in advance for any replies.

Notify once and add any calibers you might use.  Not a big deal really.

They don't have to know WHICH upper is on the gun.  I seriously doubt much would come of having a caliber that was not listed on the gun but one should try to comply with the regulations!!

Yes, form 4 shows lower serial #, barrel length, caliber.  If you want to SEE a form 4, go to      [url]www.TITLEII.com [/url]

If making yourself, you want to use the Form-1, the Form-4 is used to transfer a NFA item.

The serial # is the "registered" part, the uppers can be swapped freely, notification not really needed, as with AR-15, nothing is permanent to any degree (11.5" today, 7.5" tomorrow afternoon).