No Serial Number, can’t sell in Colorado:

[Mike Poindexter]

Just looked up the text of the bill. As I suspected, antiques under federal law and C&R eligible (although they missed the 50 year provision and went instead with 1968 or prior manufacture) are exempt.. Here is the quoted exemption language from SB 23-279:
(II) THE FIREARM INVOLVED HAS BEEN RENDERED PERMANENTLY
6 INOPERABLE; IS A DEFACED FIREARM, AS DESCRIBED IN SECTION
7 18-12-103; IS AN ANTIQUE FIREARM, AS DEFINED IN 18 U.S.C. SEC. 921
8 (a)(16); OR WAS MANUFACTURED BEFORE OCTOBER 22, 1968.

Like I said, the gunshops that should know better, don't.

[David Noble]

My gun store was undergoing an ATF compliance check about 7 years ago. One of the agents came across an Eli Whitney 32 rimfire revolver made in the 1870’s and asked why it was not not tagged with a bound book number. I explained that it was an antique and was not required to be entered into the bound book. The reply was that by law, if there was ammunition available in the normal channels of business it could not be considered an antique. I replied that you cannot readily buy ammo in that caliber as it hasn’t been manufactured for forty or fifty years. The agent said original ammo is on Gunbroker occasionally, and so it needed to be entered in my books. Trying to argue a point with an ATF agent is rarely worth the outcome. It took me a couple of years to sell the gun because no one, including C&R holders wanted to hassle with doing paperwork and background checks to get it. I ended up selling it at a loss to another dealer. I doubt that dealer logged it into his books, but it got it off of mine.
On a side note, I asked the agent about all the antique Colt SSA’s that were always being offered for sale online and at gun shows and gun stores with no FFL required or background checks. The answer was those were illegal sales.

[Nick de Guerre]

Mike, well done. That explains it...just dumb gun store guys.
I cant recall whether there was an explicit compliance date on the 1968 Act. I do know that I have read that most companies were compliant by Jan 1969.

People often say "pre-1968," when really they should say "pre-1969."

NDG

[Big D]

A dealer who posts regularly here tried to point out the numerous mistakes the ATF guy made. Net results - ATF harrassing visits weekly or monthly, to the point that he had to close his full service shop.