Colorado lawmakers are considering a bill that would place new restrictions on digital files used to produce firearms with 3D printers, including criminal penalties for possessing or sharing certain design instructions.

The legislation, HB26-1144, would prohibit individuals from creating firearms or key components using 3D printers and would also target the digital blueprints that guide the machines. The bill defines these files as “digital instructions,” such as computer-aided design (CAD) programs that can direct a printer to manufacture a firearm or its parts.

Under the proposal, possessing or distributing those instructions with the intent of producing a firearm would be illegal. A first violation would be treated as a misdemeanor, while subsequent offenses could be charged as felonies.

The measure advanced Friday in the Colorado House after Democrats moved it forward despite objections from Republican lawmakers.

Supporters say the bill builds on a 2023 Colorado law that banned the possession or sale of so-called “ghost guns,” firearms assembled by individuals that lack serial numbers. That law targeted ownership and sales but did not explicitly prohibit the process of manufacturing such weapons.

Republican lawmakers argued the proposal raises concerns about constitutional rights and free expression.

State Rep. Dusty Johnson said measures like HB26-1144 risk eroding Second Amendment protections.

“We are here to represent the voices of those who elected us to serve them,” Johnson said. “That means representing their values, not dictating what their values are and what they cannot do.”

Johnson also argued that restricting digital design files could amount to censorship.

State Rep. Ron Weinberg criticized the legislation as ineffective, arguing that people could easily bypass the restrictions by accessing the files from outside Colorado.

“Internet distribution, in case you didn’t know, is borderless,” Weinberg said. “There is no border for the internet.”

Lawmakers in Colorado are also considering another proposal that would restrict the sale or transfer of firearm barrels, limiting those transactions to federally licensed firearm dealers.