QF 3-pounder Hotchkiss

Hotchkiss 47 mm L/40 M1885 & QF 3-pounder
A Royal Navy 3-pounder gun on a central pivot mount in 1915.
Type	Naval gun Anti-aircraft gun Coastal artillery
Place of origin	France
Service history
In service	1886–1950s
Used by	See users section
Wars	See wars section
Production history
Designer	Hotchkiss
Designed	1885
Manufacturer	Hotchkiss et Cie
Produced	1886
No. built	2,950 (UK)
Variants	32 to 50 calibers in length[1]
Specifications
Mass	240 kg (530 lb)
Length	2 m (6 ft 7 in)
Barrel length	1.8 m (5 ft 11 in) 40 caliber
Shell	Fixed QF 47 × 376 mm R Complete: 3 kg (6.6 lb) Projectile: 1.5 kg (3.3 lb)[2]
Calibre	47 mm (1.9 in)
Breech	Vertical sliding-wedge
Elevation	Dependent on mount
Rate of fire	30 rpm[3]
Muzzle velocity	571 m/s (1,870 ft/s)
Maximum firing range	5.9 km (3.7 mi) at +20° 4.5 km (2.8 mi) at +80°

The QF 3-pounder Hotchkiss or in French use Canon Hotchkiss à tir rapide de 47 mm were a family of long-lived light 47 mm naval guns introduced in 1886 to defend against new, small and fast vessels such as torpedo boats and later submarines. There were many variants produced, often under license, which ranged in length from 32 to 50 calibers but 40 caliber was the most common version. They were widely used by the navies of a number of nations and often used by both sides in a conflict. They were also used ashore as coastal defense guns and later as an anti-aircraft gun, whether on improvised or specialized HA/LA mounts.