An unknown number of guns are being built with the mechanisms, causing problems for the police and ATF officials. Photo: An ATF agent holds a generic unfinished receiver, back, and one that has been manufactured, front, at an ATF field office in Washington, on May 06, 2014. The ATF is trying to crack down on the trade in the makeshift guns by targeting shops and individuals who offer to turn the unfinished receivers into functional pieces for firearms. (Photo by Bill O'Leary/The Washington Post)

A .44 Colt Dragon with a traditional Cowboy's hat. This weapon was originally used in the Mexican War of 1846-8 and it is typical of the type used in the “Wild West” of America. (Photo by Orlando /Three Lions/Getty Images). Circa 1950

A makeshift cart with containers is seen at a suspected drug tunnel under construction during a media tour by Mexican Army in Tijuana April 7, 2015. Mexican soldiers foiled the construction of a suspected drug tunnel underneath a house near the U.S. border, arresting nine people and impounding a truck used to clear debris, the Army said on Tuesday. Wired with lights, the tunnel was being built next to the Tijuana border crossing, south of San Diego, California, and near a Mexican air force installation as well as a regional federal police facility. (Photo by Reuters/Stringer)

Three prostitutes lean out of a window in Santiago, Chile, in an attempt to entice customers inside, circa 1950. (Photo by Three Lions/Getty Images)

New York Rangers right wing Ryan Reaves punches Minnesota Wild left wing Marcus Foligno (17) during a third-period fight in an NHL hockey game Thursday, October 13, 2022, in St. Paul, Minn. (Photo by Aaroan Lavinsky/Star Tribune via AP Photo)

A boy plays in water from a broken fire hydrant in Rosemead, California on Saturday, May 10, 2025, seeking relief as spring heat breaks temperature records across the Southland. (Photo by Ringo Chiu/ZUMA Press Wire/Rex Features/Shutterstock)

A cosplayer dressed as the actress Lucy Liu, as depicted in the animated series Futurama, poses for a photo at Comic-Con International in San Diego, California, U.S., July 23, 2022. (Photo by Bing Guan/Reuters)

People watch fireworks commemorating the 76th anniversary of the victory in the Great Patriotic War in St. Petersburg, Russia, May 9, 2021. (Photo by Chine Nouvelle/SIPA Press/Rex Features/Shutterstock)