In what may be the first attempt in decades to chip away at 1960s-era gun laws, a new bill in Congress would bar the government from restricting so-called “armor-piercing” rifle ammunition and could open the door to importing rifles like the AK-47.

Utah Republican Rep. Rob Bishop has submitted a bill that attacks the “sporting purposes” clause of the 1968 Gun Control Act that allows the Bureau of Alcohol, Tobacco and Firearms to determine what types of guns and ammunition are legal for over-the-counter sales in the U.S. and replaces it with a “for all lawful purposes” litmus test.

The language would better align with recent Supreme Court decisions on gun ownership for self-defense and would include legal uses not envisioned when the law was passed.

“There are some people in the United States who clearly don’t believe in the Second Amendment and want to do everything they can to ban guns, and this loophole in existing law using language that was never defined has been a gaping hole to do that,” Bishop said in an interview on NRA’s Cam & Company radio show. “It would change the mindset of the way people look at the issue of gun rights. So you’re not saying let’s ban everything then carve out exemptions for sporting purposes; what we’re saying is as long as it’s lawful don’t ban it at all.”

The bill, dubbed H.R. 2710, comes on the heels of a major defeat for the Obama Administration, which tried to ban popular “Green Tip” rifle ammunition because it determined the bullet was technically an armor-piercing round and therefore had no sporting purpose. The effort galvanized gun rights supporters, eventually forcing the ATF to back away from the ban.

“The ATF tried to ban some ammunition using this loophole and they were shamed into going backwards,” Bishop said.

READ MORE: ATF Backs Down On Popular AR-15 Ammo Ban

Additionally, Bishop’s legislation would legalize the import of firearms that are also manufactured in the U.S. that had been banned based on the ATF’s determination that they have no “sporting purpose.” That reversal could allow for importation of rifles like the AK-47, which until now had to have parts removed and be reassembled here with U.S. parts.

These weapons “are popular for use in 3-gun competition and have been arbitrarily and unfairly classified as not meeting the ‘sporting purpose’ test because ATF does not consider 3-gun shooting a sport,” the National Shooting Sports Foundation said in a release supporting Bishop’s bill. “Nevertheless, 3-gun is among the most popular new target shooting competitions nationally.”

In a 1989 evaluation of whether foreign-made “semi-automatic military assault rifles,” could be imported, the ATF determined that sporting purposes included “the traditional sports of hunting and organized competitive target shooting.”

“In addition, the working group found that the reference to sporting purposes was intended to stand in contrast to military and law enforcement applications,” the feds said at the time. “Consequently, it determined that police/combat-type competitions should not be treated as sporting activities.”

So far H.R. 2710 has more than 50 co-sponsors, including at least one Democrat, Texas Rep. Henry Cuellar. Bishop is optimistic the bill will become law, but admits there’s a lot of work to be done.

“This issue has been going on since 1989 and it’s time for Congress to step up once and for all and say this is the intent of the Constitution — it’s not just for gun collecting, it’s not for sporting activities, it is for the individual right of self defense,” Bishop said in his Cam & Company interview. “And the Supreme Court said that, so we might as well clarify it in statute as well.”