In the Imperial War Museum Review No.6, pages 4-15 is an article by Bryn Hammond - Professionals and specialists: military mining on the Western Front. It describes combat underground and a cut-down version of the .303 rifle is mentioned. Note 54 refers: A rifle of this type is illustrated in the Visit Diary of First Army Controller of Mines. PRO WO158-137. So if someone fancies a visit to Kew to find out more...!