A friend of mine has an AR made from an 80%.
It was made years ago, at least ten years ago.
He was told it has to be serialized. I don't think it does.
Is there a new law in effect that is retroactive to older guns?

See the flowcharts at the following SLFU page:
https://portal.ct.gov/DESPP/Division-of-State-Police/Special-Licensing-and-Firearms/Special-Licensing-and-Firearms

See where the friend falls on those charts.

If they have a completed firearm made from an unfinished lower and that firearm was completed prior to 10/1/2019 then they don't have to serialize the firearm right now. If they completed the firearm after 10/1/2019 then they were supposed to apply for a serial number within 30 days of manufacture.

DESPP-0419-C Unique Serial Number Application and Gun Manufactured Completion Notification

Couple of relevant statutes:

Sec. 29-36a. Manufacture of a firearm. Acquisition of unique serial number or other mark of identification. Exceptions. Penalty.
Sec. 53-206i. Manufacture of firearm from polymer plastic without detectable security exemplar. Prohibited. Penalty.

Sec. 53-206j. Sale, delivery or transfer of unfinished frame or lower receiver. Prohibited. Exceptions. Penalty.

If they have a completed firearm made from an unfinished lower and that firearm was completed prior to 10/1/2019 then they don't have to serialize the firearm right now. If they completed the firearm after 10/1/2019 then they were supposed to apply for a serial number within 30 days of manufacture.


His gun was made prior to '11.
So, he doesn't have to get it serialized?

Per the statute linked above (and the portion of text from it also posted above) it appears he would not have to serialize the firearm.

Tell them to keep an eye on the Lamont HB 6667 bill because if that passes in it's current form it may change things for those with non-serialized firearms.