sunday mail crossword

[carol_healy]

gas operated light machine gun used by british forces in the secon world war 4 letters  ?r?n

[Jules001]

Bren - although not sure about the gas operated bit.

[Philtaz]

The gas bit actually refers to the expended gases from the cordite which when ignited expels the round from the cartridge.  The 'gas' is channelled into a separate chamber next to the barrel which has a piston inside.  When activated the piston pushes back the breech/working parts, which expel the empty cartridge then reload the next round into the chamber as they return forward.