House lawmakers passed the legislation, entitled the Protecting Our Kids Act, in a series of votes that fell mostly along partisan lines.
The legislation is intended to "provide for an increased age limit on the purchase of certain firearms, prevent gun trafficking, modernize the prohibition on untraceable firearms, [and] encourage the safe storage of firearms," according to the bill text.
The bill would raise the minimum purchasing age for semiautomatic centerfire rifles and shotguns capable of carrying more than five rounds of ammunition. The legislation would also place restrictions on firearms assembled using components that are difficult to trace.
Additionally, the legislation would also mandate safe storage of firearms in residences with minors or those otherwise ineligible to possess a gun, establish best voluntary practices for firearm storage through the Attorney General, and require gun manufacturers to provide written notices saying "safe storage saves lives" with every firearm.
The legislation also contains sections restricting access to large capacity ammunition feeding devices and closing the so-called "bump stock loophole" that allows for the sale of devices enabling semiautomatic weapons to be quickly fired.
Previous efforts to tighten gun laws have been struck down in the Senate because of the so-called filibuster, which requires 60 votes in the 100-seat chamber. The so-called nuclear option, removing the filibuster, would allow Democrats to use their slight majority to pass something, but a couple lawmakers within their own party have refused to approve such a tactic.
Although Minority Leader Mitch McConnell has, according to CNN, privately expressed openness for raising the purchase age to 21, most Republicans are opposed to it.