The powers that the ATF have are the same as any other law enforcement officer although the ATF also has powers to investigate and prevent federal offenses that involve the unlawful use, possession or manufacture of firearms and explosives as well as acts of arson and bombings and illegal trafficking of alcohol and tobacco products.
ATF agents are special agents like FBI, DEA, IRS have powers of arrest.
An ATF agent can arrest you when they have a legal reason to make an arrest just like regular police can.
The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) is the federal agency primarily responsible for administering and enforcing the criminal and regulatory provisions of the federal laws pertaining to destructive devices (bombs), explosives, and arson.
Specifically, ATF Special Agents have lead investigative authority on any federal crime committed with a firearm or explosive, as well as investigative authority over regulatory referrals and cigarette smuggling.
Under the United States Constitution, only the Legislative branch of the government can create laws.
The ATF is an agency of the Justice Department, which is part of the Executive branch, which cannot create laws.
As sworn law enforcement officers, special agents are authorized to carry weapons and make arrests for federal offenses against the United States.
The term "any other weapon" means any weapon or device capable of being concealed on the person from which a shot can be discharged through the energy of an explosive, a pistol or revolver having a barrel with a smooth bore designed or redesigned to fire a fixed shotgun shell, weapons with combination shotgun and rifle.
On January 31, 2023, the ATF published a politically driven ruling which noted that attaching a pistol brace to a rifle with a barrel under 16 inches would make that firearm an NFA short-barreled rifle (and thus subject to additional regulation and tax).