A corrected recollection of 40 mm aircraft-gun trials

Did the large aircraft-gun installation recalled during the Sunderland discussion use a pom-pom?

The recollection is corrected to a Bofors 40 mm and then to Beaufighter trials, so it does not establish a pom-pom installation on a Sunderland.

A question about fitting a pom-pom to a Sunderland prompts a correction: the remembered weapon is identified as a Bofors 40 mm. The discussion then turns to Beaufighter tests said to compare Vickers and Bofors 40 mm guns on the same aircraft. The recollection favors the Bofors but treats such a large aircraft gun as appropriate only for a specific task. The exchange does not establish that a Sunderland carried the installation being recalled.