QF 13 pounder 6 cwt AA gun

• Name — QF 13 pounder 6 cwt anti-aircraft gun • Origin — United Kingdom • Type — Anti-aircraft gun • Is Ranged — yes • Is Artillery — yes • Is Uk — yes • Service — 1915–1918 • Used By — British Empire • Wars — World War I • Number — 20 • Part Length — Bore: 5 ft; Total: 6 ft • Caliber — 3 in • Cartridge — 12.5 lb Shrapnel; later HE • Max Range — 17000 ft • Recoil — hydro-spring, constant, 25 in • Carriage — high-angle mounting on lorry • Elevation — 0°–70° • Traverse — 360°

• Illustration — On Mk I mount, on a Daimler Mk 3 lorry This was a standard QF 13 pounder field gun barrel and breech with the addition of a retaining catch to the breech to retain the round when loading at high angles. It was first approved in October 1914 and was issued on Mk I high angle mounting, usually mounted on a motor lorry. The Mk I mounting had an additional recuperator housing mounted directly above the normal recuperator to facilitate gun runout at high angles. Hence the appearance was of a gun barrel with 2 slightly shorter tubes of similar diameter above it. Mk II mount improved the usability, added deflection gear and the recoil system was improved so that the additional recuperator became unnecessary and was removed. On the Mk II mount the gun has the appearance of a standard 13 pounder. The mount design was unusual in having both gunlayers on the left side. Following World War I, the guns were returned to service as standard 13 pounder field guns.

The gun's performance was "ballistically poor" and it was only marginally effective against aircraft. It was relegated to minor war theatres and the 13 pounder 9 cwt and 3 inch 20 cwt guns took over the major anti-aircraft role. At the end of World War I there were only 20 of the guns in service worldwide, with 12 in Egypt and Palestine, 4 in Mesopotamia, 2 in Greece (Salonika front) and 2 on the Western Front.

Performance of British World War I anti-aircraft guns • Gun — muzzle velocity — Shell weight — Time to 5000 ft at 25° (seconds) — Time to 10000 ft at 40° (seconds) — Time to 15000 ft at 55° (seconds) — Max. height • QF 13 pounder Mk III — 1600 ft/s — 12.5 lb — 17000 ft • QF 13-pounder 9 cwt — 1990 ft/s — 12.5 lb — 10.1 — 15.5 — 22.1 — 19000 ft • QF 12-pdr 12 cwt — 2200 ft/s — 12.5 lb — 9.1 — 14.1 — 19.1 — 20000 ft • QF 3-inch 20 cwt (1914) — 2500 ft/s — 12.5 lb — 8.3 — 12.6 — 16.3 — 23500 ft • QF 3 inch 20 cwt (1916) — 2000 ft/s — 16 lb — 9.2 — 13.7 — 18.8 — 22000 ft • QF 4-inch Mk V — 2350 ft/s — 31 lb (3 c.r.h.) — 4.4 — 9.6 — 12.3 — 28750 ft

The canonical record carries the following identifying particulars. Classified as an anti-aircraft gun. The register further records that qF 13 pounder 6 cwt AA gun is associated with United Kingdom of Great Britain and Ireland.