How effective was the Pom-Pom against Stukas?

How effective was the Pom-Pom against Junkers Ju 87 Stuka dive bombers?

It was useful, and many attacks missed or were disrupted, but histories overrepresent the successful strikes and therefore make the defense look weaker than it was.

Published narratives concentrate on successful air attacks because damage and sinking create the memorable story. Unsuccessful sorties can disappear into a sentence even though misses were common and anti-aircraft fire helped produce them. The Pom-Pom and Bofors could both elevate to roughly 80 degrees, so the Tribal class's limited 4.7-inch mount should not be mistaken for a 40 mm elevation problem. Anti-aircraft effectiveness includes attacks broken up, pilots hurried, and bombs or torpedoes sent wide as well as aircraft shot down.