Atomic Cannon 60th Anniversary 1/32 Renwal Revell In May 1953, the Upshot-Knothole tests proved that the M65 Atomic Cannon could fire a 16 kiloton yield nuclear weapon seven miles (11.3 km). It used the same warhead that Oppenheimer had helped create. The United States constructed twenty of these weapons and deployed them to Europe and Korea as deterrents against a communist invasion.