A quote from the book "The Shooting Field with Holland & Holland" by Peter King:

"German Zeppelin airships flying over England were brought down by a Holland & Holland 12-bore shotgun. This arm, of which it is believed 200 were made and only two are known to survive, was designed by Holland & Holland and employed a special 'Duplex' (or two stage) choke bore. The weapon was actually made by Webley & Scott in Birmingham, and was issued to Royal Naval Air Service units probably in 1914. Cartridges, which were produced in all-brass and paper case forms, were loaded with 'chain shot', one large ball and six small on a wire, and were intended to damage struts and fabric."