20" upper on AR-15 registered with a 16" barrel?

[Mass-diver]

When I bought my AR (new) it came with a 16" barrel. If I want to put a 20" barrel on it, either permanently or temporarily (swapping it back and forth with the 16" setup) will I be breaking the law? Do I need to pick one length? If I choose 20" do I need to 're-register' the rifle?
Thanks!

 

[Chipperman]

It just needs to be at least 16".
Change other lengths or calibers at will.

 

[kevin9]

When I bought my AR (new) it came with a 16" barrel. If I want to put a 20" barrel on it, either permanently or temporarily (swapping it back and forth with the 16" setup) will I be breaking the law? Do I need to pick one length? If I choose 20" do I need to 're-register' the rifle?
Thanks!

There should be no problems switching uppers/barrels as long as the barrel is at least 16" and is compatible pre-ban/post-ban wise (e.g. no flash suppressors or bayonet lugs on post-ban receivers).

No new FA10 is required. As I understand it FA10s are technically the registration of the sale/purchase/transfer of a gun, not registration of the gun itself. For example, that's why they are not required if one moves into the state with guns.

You bought it with a 16" barrel and the sale was registered as such. Changing the barrel does not constitute the acquisition of a new gun as it is the same lower receiver. You're merely changing some parts on the same gun.

 

[Half Cocked]

If I choose 20" do I need to 're-register' the rifle?
Thanks!

No

 

[Mass-diver]

Thanks Guys!

 

[vellnueve]

No, because for one thing it's not a registration. FA-10s are a record of transfer, nothing more.