A new congressional proposal to ban bump stocks in the wake of the Las Vegas mass shooting would actually ban all semi-automatic rifles and parts.

A new gun control proposal in Congress that is being pitched as a bipartisan bump stock ban would actually ban all semi-automatic rifles in the United States, according to an analysis of the proposed bill.

The legislation, which was drafted by Rep. Carlos Curbelo, a Florida Republican, never bans bump stocks by name. Instead, the proposal bans any person from possessing or making any part that could be used to increase the rate of fire in any semi-automatic rifle. The lead co-sponsor on the gun control bill is Rep. Seth Moulton, a Massachusetts Democrat and U.S. Marines veteran who completed four tours of duty in Iraq.

“It shall be unlawful for any person … to manufacture, possess, or transfer any part or combination of parts that is designed to increase the rate of fire of a semi-automatic rifle,” the bill states. At no point does the proposed legislation specify a base rate of fire against which any illegal increases would be judged, a potentially fatal flaw in the bill’s drafting. As a result, the proposal arguably institutes a federal ban on any and all parts that would allow the gun to fire at all, since the mere ability to fire a semi-automatic weapon by definition increases its rate of fire from zero.

The design of semi-automatic weapons uses the recoil of the weapon generated by the gas explosion in the chamber when a round is fired to automatically chamber a new round, and prepare the weapon to be fired again. Because of this, any parts used in that process would likely be subject to the federal ban proposed in the Curbelo/Moulton bill, since they serve to increase the rate of fire of a semi-automatic weapon. Gas tubes, gas blocks, buffer springs, magazines, charging handles, ejectors and extractors, and even triggers themselves could potentially be banned under the bipartisan bump stock ban language proposed by Curbelo and Moulton.

The @NRA is opposed to the new bump fire stock ban legislation https://t.co/LkllbBzlM9 — Stephen Gutowski (@StephenGutowski) October 12, 2017

It arguably bans *any* part of a gun that allows the gun to fire. pic.twitter.com/KUBZJUTBnZ — Sean Davis (@seanmdav) October 12, 2017

The proposal also creates significant implementation challenges, since it contains zero grandfather provisions for existing gun owners or manufacturers. The bill also fails to provide any means by which existing gun owners and manufacturers could turn in their weapons to federal authorities to avoid running afoul of the bill’s effective ban on the possession of any semi-automatic firearms or parts. Absent a statutory federal gun buyback, which is not included in the Curbelo/Moulton bill, it does not appear that current law-abiding gun owners and manufacturers would have any way to abide by the constraints of the law in good faith absent a massive federal confiscation effort.

The National Rifle Association announced on Thursday that it opposed the Curbelo/Moulton proposal. In a separate statement, the organization said the Bureau of Alcohol, Tobacco, Firearms And Explosives (ATF) already had the legal authority necessary to ban bump stocks and that additional legislation was unnecessary. The group noted that bump stocks were originally approved by the Obama administration in 2010.

It is unclear at this time whether Curbelo and Moulton intended to propose such an expansive ban on all semi-automatic rifles in the United States. Also unknown is why the authors of the proposal chose to target rates of fire across all weapons instead of specifically banning bump stocks themselves, which consist of a single grip and stock assembly that is designed to rock a rifle back and forth against an individual’s finger in order to increase the rate of fire of a semi-automatic rifle weapon.

Neither Curbelo’s nor Moulton’s office responded to repeated requests for comment and clarification on the design and intent of their gun control proposal.