#self-propelled-gun (2 Posts) The M65 Atomic Cannon: The Secret Nuclear Weapon That Could Have Changed History In the 1950s and 60s, nuclear weapons like the M65 Atomic Cannon were developed, but their tactical effectiveness was limited. 2023.11.19 17:43 Secret Weapon Unleashed: The M1299 ERCA – America's Ultimate Arsenal! The U.S. is developing the M1299 ERCA to respond to changing battlefield conditions with a range of up to 43.5 miles. 2023.11.18 17:42