registered it as a multi caliber SBR. That way I can swap over to 5.56 or other if ever desired.
ince last year or so, the BATFE no longer accepts multi caliber on the form 1,3or4, they require one caliber, however they do accept others in the decription box. On the other hand you donot have to have multi caliber or list any others but "one" since it's registration is as a SBR/SBS not a caliber, therefore you can put any upper you wish on there even one shorter than described in the form. They do however ask that if it is a PERMANENT change that you simply send them a typed letter indicating the change and they will stamp it and send it back to you if you wish.
I talked to Mrs. Dawn at the branch about this a year or so ago and she stated this to me, and she also said there would be a posting on the website or a update to the forms but I havenot searchd for it since its kinda a waste of time anyhow :thumbup: