Appeals court narrows Colorado gun law, leaving 3D-printed frames in focus

A federal appeals court just drew a tighter line around Colorado’s ghost-gun law, and that line matters most for anyone printing, finishing, or assembling frames and receivers at home. The Tenth Circuit said Colorado’s manufacturing ban reaches making a frame or receiver from raw material, but not completing, assembling, or converting an unfinished frame that was already manufactured. In plain maker terms, the court treated raw-material manufacturing differently from the last-step work many hobbyists associate with kits and unfinished receivers.

The case, National Association for Gun Rights v. Polis, ended in a mixed 2-1 ruling filed on April 23, 2026. The panel also addressed Colorado’s possession and purchase provisions, then sent part of the case back for further constitutional analysis. That leaves the state’s law intact in broad outline, but not without friction over where the statute stops and where home manufacturing begins.

Colorado’s law, signed by Gov. Jared Polis on June 2, 2023, took effect on January 1, 2024. It prohibits the purchase, sale, transfer and possession of unserialized firearms, firearm frames or receivers, and firearm parts kits. It also requires existing unserialized firearms, frames or receivers to be marked by a licensed dealer, and multiple violations can rise to felony offenses. Gun-rights groups challenged the law almost immediately, arguing that Colorado was trying to regulate home manufacturing and 3D printing too aggressively.

That fight did not stop at Senate Bill 279. The Colorado General Assembly also enacted HB26-1144 in 2026, and that bill goes even further by prohibiting knowingly manufacturing or producing a potentially functioning firearm, unfinished frame or receiver, large-capacity magazine or rapid-fire device by 3-dimensional printing. It became law on April 15, 2026, putting desktop fabrication squarely in the crosshairs.

The broader policy backdrop is the federal ghost-gun fight. The Bureau of Alcohol, Tobacco, Firearms and Explosives defines privately made firearms as guns completed or assembled by someone other than a licensed manufacturer and lacking a manufacturer’s serial number. The Supreme Court of the United States upheld the Biden administration’s ghost-gun rule in March 2025, and ATF data cited in recent reporting showed 92,702 suspected privately made firearms recovered and traced from 2017 through 2023, with crime recoveries climbing from 1,629 in 2017 to 27,490 in 2023. For makers, the immediate takeaway is the same one Colorado’s new law and the appeals ruling keep forcing into focus: files, kits, unfinished frames and finished, unserialized receivers are no longer playing by the same rules.