§ 1.4 defined a privately made firearm as one produced by someone other than a licensed manufacturer and never given a serial number by one. This is the point at which that definition becomes an obligation. A licensee must legibly and conspicuously identify each privately made firearm — a PMF — received or otherwise acquired, INCLUDING from a personal collection, not later than the seventh day following the date of receipt or other acquisition, or before the date of disposition (including to a personal collection), whichever is sooner. The duty attaches on acquisition rather than on sale, so a PMF taken in and set aside is already on a clock.

The inclusion of a personal collection at both ends of that sentence is deliberate and worth dwelling on. A licensee who moves a PMF out of their own collection into the business, or the reverse, has done the thing that starts or ends the duty; the transaction that feels least like a trade is squarely inside it. Chapter 3 made a related point about closing inventory, and the same instinct is at work in both — the regulation is closing the routes by which a firearm could pass through licensed hands without being identifiable afterwards.

A transitional rule covers the firearms already on hand when the requirement arrived, and it has not expired. Licensees shall identify, or cause another person to identify, each privately made firearm received or otherwise acquired before August 24, 2022 within sixty days from that date, OR prior to final disposition (including to a personal collection), whichever is sooner. The second limb has no end date: a pre-2022 PMF still sitting in inventory has not been finally disposed of, so the duty attaches on the day it moves. One further definitional point ties this back to the trade: placing marks of identification on privately made firearms is expressly within the gunsmith definition in § 478.11, so a licensee doing this work for others is doing gunsmithing rather than manufacturing — provided they are not completing, assembling or coating firearms into a usable state, which requires a manufacturer’s license.