Because it did not have one. Seroiusely they sighted it by looking down the barel, i fire it the same way by paging down to look down the length of the barel. The adation of this gun to some PT boats was an add hock affair and they were used for barge busting duties in the Pacific. Which is prety much what PT's were gloarified barge busters, despite what Hollywood would have use beleave. The Italians actualy snk far more Warship tonage with the MTB's than anyone else. the Germans more overall tonage with their's.
