No Serial Number, can’t sell in Colorado:

[6pt-Sika]

Originally Posted by Larry Stauch

Obviously, this law and others like it are not pointed at the antiques and C&Rs out there. They're focused on the black gun crowd and all others just get painted with that brush. If you think the states like Kalifornia, New York, Illinois and Colorado are passing these gun laws to please we sportsman, hunters, shooters and collectors they are not. They are doing just the opposite to harass all gun owners and provide as much discouragement as possible, hoping we'll all think it's too much trouble to own a gun and give them up; IMHO...

BTW, I just copied that off of some attorney's web site.

Used to be AR uppers weren’t serialized now if I’m not mistaken the ATF made it necessary for new manufacture uppers to be serialized . Think that came about in the last year or two .