Cannon like that can fire nuclear shells of about 15 kilotons, which roughly corresponds to the bomb dropped on Hiroshima.
On this day the first nuclear shell was fired out of a cannon. It happened at the American nuclear testing site in Nevada, only a few hundred kilometers from Las Vegas. It was the first and last such event in history. The atomic cannon M65, nicknamed “Atomic Annie”, was used to fire the shell. It was a 280 mm cannon over 25 meters in length. The weight of the complete weapon exceeds 83 tons and its 364 kg shells have a range of about 32 km. What is specific about the atomic cannon is what was in the shell. Specifically, a nuclear W9 type bomb of 15 kilotons was placed within. This force approximately corresponds to the bomb dropped on Hiroshima in 1945 and has a destructive power equivalent to 15,000 tons of TNT. This means that one atomic cannon can destroy a whole city with a single shell.
On this day, the American Secretary of Defense attended the test in person, as did the Chief of Joint Staff of the United States. The cannon fired a shell at a distance of about 10 kilometers. After 19 seconds of flight, the shell exploded 160 meters above the ground. The blast was of the expected strength of 15 kilotons, like Hiroshima. After successful testing, the army contracted about 20 of these cannons and deployed them in Europe and Korea. In case of war, these cannons were intended to be used for the so-called tactical nuclear warfare (as opposed to strategic weapons like long-range rockets). The United States have to this day conducted an incredible 928 nuclear tests on the test area in Nevada.