Form 4's

[redondhed]

My Vector Arms UZI's Form 4 lists the caliber as: ".45/.22/9MM"  The one for my M-16 just says ".223." I have been told that if I put my 9MM upper on the M-16 it is still O.K. and legit.  Does anyone want to speculate on why somebody thought it necessary to include all 3 on the Uzi registration? :D

[whiskerz]

The atf has a form and wants to be notified of changes in description of the weapon.   :uzi:

[RoverDave]

I've been told by class III & class II dealers that it's not a big deal to pop on an upper of a different caliber for an afternoon of shooting but that you need to get the form 4 changed if you wanted to make a permanent change to the caliber or length of the barrel. Or course that's just their opinion, but you could also ask different ATF agents and get different opinions as well. There's really only one way to be completely safe.

[dustindu4]

you just need to send them a letter of intent saying you're going to use a different caliber and they'll just say ok.  When I buy a DIAS I'm going to put .223, .308, .50 AE and .50 Beowulf on my form 4.