It’s undeniable that the U.S. military houses some of the deadliest and most powerful rifles ever. From assault rifles to battle rifles, the military surely has it all. In fact, some of these rifles were owned by the military during the Cold War, which have been upgraded, making the U.S. military even more dangerous. Some of the deadliest rifles owned by the U.S. military include M4A1, FN SCAR, and M27 infantry automatic rifles. The U.S. military also owns M14, Mk 14 enhanced battle rifle, and M39 enhanced marksman rifle.