Some State and Federal prisons back in the 20's through the 60/70's had 1917 Brownings mounted in their guard towers. https://smallarmsreview.com/the-san-quentin-browning-machine-gun/
Back in, ca. 1984 the Texas Department of Public Safety sold 5 M2 .50's and 20 ANM2's at public auction. They had been in use at the TDC (Texas Department of Corrections). I ended up with the 5 M2's. They also sold around 20 Thompsons. Unfortunately, some of them did not have papers.