Question: what caliber are gatling guns?
Answer: The US Army adopted Gatling guns in several calibers, including .42 caliber, .45-70, .50 caliber, 1 inch, and (M1893 and later) .30 Army, with conversions of M1900 weapons to .30-03 and .30-06. The .45-70 weapon was also mounted on some US Navy ships of the 1880s and 1890s.