7.7 cm Feldkanone 16
Type	Field gun
Place of origin	German Empire
Service history
In service	1916–1945
Used by	German Empire Bulgaria China Finland[1]
Wars	World War I Spanish Civil War World War II
Production history
Designer	Krupp
Manufacturer	Krupp
Produced	1916–1918
No. built	3,020+
Specifications
Mass	1,318 kg (2,906 lb)
Barrel length	2.695 m (8 ft 10 in) L/35
Shell	Separate loading, cased charge and projectile 77 x 230mm R[2]
Caliber	77 millimetres (3.0 in)
Breech	horizontal sliding-block
Recoil	hydro-spring
Carriage	box trail
Elevation	-10° to +40°
Traverse	4°
Muzzle velocity	545 m/s (1,790 ft/s)
Effective firing range	9,100 m (10,000 yd) 7.2 kg (16 lb)(HE shell)
Maximum firing range	10,700 m (11,700 yd) (gas shell)

The 7.7 cm Feldkanone 16 (7.7 cm FK 16) was a field gun used by Germany in World War I. Most surviving examples in German service were rebarreled after the war as the 7.5 cm FK 16 nA (neuer Art, meaning "new model"). A total of 298 guns of the old type were still in German army service in 1939, making it the oldest field artillery piece in German inventory at the beginning of the Second World War.

History

The older 7.7 cm FK 96 n.A. field gun was very mobile, but, once the war settled into trench warfare, its lack of range became a serious disadvantage. The FK 16 was intended to remedy this problem. The barrel was lengthened and it was given a box carriage to allow for greater elevation, which increased the range. It was also given separate-loading ammunition to reduce powder consumption and barrel wear at short ranges, although this had the drawback of reducing the rate of fire compared to the older gun.

It was prematurely rushed into production in 1916 and early guns suffered from a number of defects, mainly stemming from the German use of substitute materials to reduce consumption of strategic metals. It also suffered from a large number of premature detonations of its shells during 1916. These were traced to poor quality control of its shells, which were sometimes too large in diameter, and problems with the picric acid used as high explosive filler in lieu of TNT. The picric acid would form very sensitive picric salts within days of filling the shells and would often detonate from the shock of firing. Lacquering the insides of the shells and spraying them with a turpentine/starch solution neutralized the picric acid and prevented it from forming picric salts.

The barrel of this gun was mounted on the carriage of the 10.5 cm Feldhaubitze 98/09 as the 7.7 cm Kanone in Haubitzelafette (i.e. "cannon on howitzer carriage") to allow it greater elevation and range.^[3]

Belgium modified the guns it received as post-war reparations as the Canon de 75 mle GP II and the Canon de 75 mle GP III. After the war, some guns were retained by Germany, re-barreled into 75mm caliber, and used in World War II as the 7.5 cm FK 16 nA.