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 woman poses for photographs after Gucci Cruise 2024 collection fashion show at the Gyeongbok Palace in Seoul, South Korea on May 16, 2023. (Photo by Kim Soo-Hyeon/Reuters)

US Navy personnel walk on the flight deck aboard the USS Nimitz (CVN-68) aircraft carrier during its port visit to Busan on March 28, 2023. (Photo by Anthony Wallace/AFP Photo)

A Ukrainian serviceman of the 65th mechanized brigade smoke on position of a Soviet-made 2s1 Gvozdyka 120mm howitzer in the Zaporizhia region, Ukraine, 15 November 2023, amid the Russian invasion. Russian troops entered Ukrainian territory in February 2022, starting a conflict that has provoked destruction and a humanitarian crisis. (Photo by Kateryna Klochko/EPA)

This photo released by North Korea's official Korean Central News Agency (KCNA) on June 7, 2012 shows North Korean leader Kim Jong-Un (C) surrounded by members of the Korean Children's Union (KCU) organizations during a joint national meeting to celebrate the 66th anniversary of the KCU organizations at Kim Il-Sung Stadium in Pyongyang on June 6, 2012. (Photo by AFP Photo/KCNA via KNS)

A dog wearing a hat, a pair of sunglass and a lei standing in a fountain of water on August 5, 2022 in Hong Kong, China. The Hong Kong SongKran Festival will be held in a shopping centre from August 5 to 9. (Photo by Vernon Yuen/Rex Features/Shutterstock)

A woman pushes a child aboard a plastic basin as they wade through floodwaters brought about by Super Typhoon Noru on September 26, 2022 in San Miguel, Bulacan province, Philippines. Super Typhoon Noru made landfall in the Philippines overnight, causing widespread flooding and leaving at least five dead. High winds and heavy rains have flattened villages and have increased the threat of landslides. (Photo by Ezra Acayan/Getty Images)

A Ukrainian service member smokes near a frontline, amid Russia's attack on Ukraine, in Donetsk region, Ukraine on February 8, 2023. (Photo by Yevhenii Zavhorodnii/Reuters)