The Welinbreechblock was a revolutionary stepped, interrupted thread design for locking artillery breeches, invented by Axel Welin in 1889 or 1890. Shortly
bottom and face of the breechblock using a rifle-calibre tube insert to initiate firing of the bagged charge) utilising 0.5inch (12.7 mm) tubes were replaced
guns consisted of a tube and 4.5-metre jacket with a hand-operated Welinbreechblock. Cloth bags contained 14 kg (30 pound) charges of cordite or flashless