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)

Britain's Prime Minister Boris Johnson gestures during a visit to Darnford Farm in Banchory near Aberdeen in Scotland on September 6, 2019. Prime Minister Boris Johnson heads to Scotland on Friday in campaign mode despite failing to call an early election after MPs this week thwarted his hardline Brexit strategy. (Photo by Andrew Milligan/Pool via AFP Photo)

Yeshiva School students briefly dance on Grant Street after the menorah lighting outside of the City-County Building for the fifth night of Hanukkah, Thursday, December 26, 2019, in downtown Pittsburgh. (Photo by Alexandra Wimley/Pittsburgh Post-Gazette via AP Photo)

A Ukrainian servicewoman fires a 2S7 Pion self-propelled gun at a position, as Russia's attack on Ukraine continues, on a frontline in Kherson region, Ukraine on November 9, 2022. (Photo by Viacheslav Ratynskyi/Reuters)

A Haka is performed before the ceremonial departure of the 'vaka' or traditional canoes ahead of their cross-Pacific voyage from Viaduct Harbour on April 13, 2011 in Auckland, New Zealand. Powered by sun and wind only, the 15,000 nautical mile journey to Hawaii via French Polynesia will set off on April 15, aiming to raise awareness of environmental issues such as ocean noise pollution, acidification and anoxic waters, whilst recapturing traditional Pacific voyaging. The votyage is named “Te Mana o Te Moana” meaning “The Spirit of the Sea”. (Photo by Phil Walter/Getty Images)

In this handout provided by Maritime New Zealand, MV Rena is seen in two pieces after overnight bad weather pounded the vessel, on January 8, 2012 in Tauranga, New Zealand. (Photo by Maritime New Zealand via Getty Images)

A Lebanese man is reflected in a pool of dirty water as he casts his fishing pole from a rocky coastal area along the Beirut coastline, Lebanon, Monday, October 3, 2016. (Photo by Hassan Ammar/AP Photo)

Italian singer Elodie performs on stage at the Ariston theatre during the 71st Sanremo Italian Song Festival, in Sanremo, Italy, 03 March 2021. The festival runs from 02 to 06 March. (Photo by Ettore Ferrari/EPA/EFE)