The 155mm W48 nukes were real nukes, but very inefficient. One 155mm nuclear shell weighed 54kg and had a yield of 0.072 kilotons of TNT. A 16" nuclear shell

The 155mm W48 nukes were real nukes, but very inefficient. One 155mm nuclear shell weighed 54kg and had a yield of 0.072 kilotons of TNT. A 16" nuclear shell weighed about 20x as much but had a 200x greater yield (15-20 kilotons of tnt)