Two major gun control policies backed by Democrats passed out of their respective chambers on Monday in the Colorado legislature. 

House Bill 1144, which would ban the manufacture and sale of 3D-printed guns and certain gun components, such as frames and receivers, passed the House in a 40-25 vote. Lawmakers in the Senate also voted 19-16 to pass Senate Bill 43, which would restrict the sale or transfer of gun barrels to only federally licensed firearm dealers. 

Both measures passed largely along party lines and now head to the opposite chamber for further consideration. Democrats hold large majorities in both the House and Senate, making it likely that both bills will make it out of the legislature and to Gov. Jared Polis’ desk. 

Republicans uniformly opposed the bills, which they said infringed on Second Amendment gun rights. Gun control legislation has been a top priority for Democrats ever since they took complete control of state government in 2019. Several of the gun bills they’ve introduced this session would expand past efforts. 

Supporters of HB 1144 say the measure is aimed at further cracking down on the proliferation of untraceable “ghost guns,” which can be 3D-printed and are turning up more at crime scenes. A January report from the Bureau of Alcohol, Tobacco, Firearms and Explosives found that the number of privately-manufactured guns recovered at crime scenes surged from 1,629 in 2017 to 27,490 in 2023. 

“Colorado has led on gun safety, passing laws that reflect our values of responsibility, safety and community,” Rep. Lindsay Gilchrist, a Denver Democrat and prime sponsor of HB 1144, said during debate Monday on the House floor. “This bill addresses this serious and growing problem in our cities and in our state,” Rep. Lindsay Gilchrist, D-Denver, said during debate Monday on the House floor. 

Along with Gilchrist, HB 1144 is sponsored by Rep. Andrew Boesenecker, D-Fort Collins, and Sens. Tom Sullivan, D-Centennial, and Katie Wallace, D-Longmont.

The measure builds on legislation passed in 2023, which banned the sale and possession of guns without serial numbers, as well as the manufacture of certain gun parts. 

Along with banning the manufacture of ghost guns, HB 1144 also prohibits selling or distributing instructions for how to print a 3D gun. Violating the law would result in a Class 1 misdemeanor, punishable by up to one year in jail, while repeated violations would be a Class 5 felony, which can result in up to three years of jail time. Licensed gun manufacturers or accredited gunsmithing programs would be exempt from the bill.  

Republicans argued the bill would violate not just Second Amendment rights but also First Amendment rights due to the provision banning the sale and distribution of 3D printing instructions.

“We’ve continued to view the right to bear arms as integral and within this right is the right to not just own and possess a firearm but to be able to repair and maintain in good working condition that firearm,” said Rep. Matt Soper, R-Delta, “and if someone has to print on a 3D printer something that makes their firearm safe, they should have the right to do so.” 

Democrats say the Senate Bill, SB 43, is also aimed at further regulating ghost guns, since the measure targets gun barrels that aren’t sold by licensed firearm dealers and could otherwise be 3D printed. The bill carries a penalty of up to $500 in fines and 30 days in a county jail for violators. 

SB 43 would also ban anyone under the age of 18 from purchasing or acquiring a firearm barrel and would require firearm dealers to keep records of barrel sales, including the buyer’s name, for at least five years. The bill does not apply to sales and transfers to law enforcement agencies and voluntary firearm buyback programs. 

The measure is led by Sen. Tom Sullivan, a Centennial Democrat who has been a lead proponent of gun safety legislation at the Capitol since his son, Alex, was killed in the 2012 Aurora theater shooting.

“Gun deaths here in the state of Colorado are not inevitable,” Sullivan said during debate Monday in the Senate, shortly before lawmakers voted to pass SB 43. “We as a society can do something about that.” 

Along with Sullivan, the measure is also sponsored by Reps. Meg Froelich, D-Englewood, and Kyle Brown, D-Louisville.

Senate Republicans argued the bill amounted to another infringement on Second Amendment rights and raised concern over the measure’s record-keeping requirements for barrel sales. 

“There’s a real sense of worry in my district, and all over the state, about another opportunity to make us get in line, give our name, our address, our birthdate, over something that probably doesn’t need to be done,” said Sen. Marc Catlin, a Montrose Republican. 

HB 1144 and SB 43 aren’t the only gun-related measures being advanced this year by Democrats. 

Senate Bill 4, which would expand the list of groups that can petition a judge to temporarily remove someone’s firearms under the state’s “red flag” law, passed the Senate last month and is being considered in the House. 

Another measure, House Bill 1126, which would require firearm dealers to have a state permit to transfer firearms, not just to sell guns, as well as place new records-keeping requirements and security restrictions on most gun sales, passed its first committee vote on Monday.