This is the Sig Sauer MPX, a modern submachine gun designed for military and law enforcement use, or in semi-automatic form, available for purchase as an NFA item as a SBR (short barreled rifle).


Thanks to the Hughes Amendment to the Firearm Owners Protection Act, no civilian can purchase the selective-fire version of the MPX, and most people won’t opt to go through the excruciatingly long (and getting longer) process of obtaining the SBR through the NFA process.

In order to sell the MPX to the civilian market, the MPX-C was created, which will be a semi-automatic with a 6.5′ barrel with 9.5″ muzzle brake permanently attached to get it up to the legal barrel length minimum of 16″ so that it can be sold as a conventional rifle without the headaches of going through the NFA process.


Or at least that was the plan, before the ATF’s Firearms Technology Branch (the same idiots who have classified string and airsoft guns as machine guns, and who have been harassing EP Armory and Ares Armor with seemingly arbitrary rulings). The ATF has now told Sig that the MPX-C’s muzzle break constitutes a “silencer,” even though it does not reduce sound, and in fact makes the gun louder as it vents gasses to control recoil.

Sig sees this determination costing the company millions in lost revenue, and is now taking the ATF to court:

Gun maker Sig Sauer has filed a civil suit against the federal Bureau of Alcohol, Tobacco, Firearms and Explosives claiming the federal agency wrongfully classified a “muzzle brake” Sig designed to reduce recoil, as an item “intended only for use” when making a silencer.

Sig claims that gun silencers are “subject to burdensome legal requirements” and by calling its muzzle brake a part for a silencer, the federal agency is subjecting it to “economic injury.”

“If classified as a silencer, no market exists for the subject device given that it will not silence, muffle, or diminish the report of a firearm and yet it would still be subject to the burdensome requirements set forth above as if it really is a silencer,” Sig argues through Manchester attorney Mark Rouvalis and Virginia attorney Stephen Halbrook.

ATF Director B. Todd Jones is named as defendant in Sig’s lawsuit and has 21 days, after being served, to respond to the civil action, dated April 7.

Sig claims it designed the muzzle brake which “effectively reduces recoil and muzzle rise when a shot is discharged” and as such, it’s not subject to regulation under the federal Gun Control Act.

It has been decades since the ATF has performed a useful function that benefits the American people. The primary goal of the organization seems to be to run interference for a federal government that seems increasingly focused on stripping American citizens of their Second Amendment rights entirely, one harassing, constricting move at a time.

The ATF serves no useful function for the citizenry. It is time to defund and disband this useless relic that hasn’t been needed since Prohibition was repealed, December 5, 1933.