Bofors 40 mm Automatic Gun L/70

Bofors 40 mm Automatic Gun L/70
British Bofors 40 mm Gun L/70 on a 1950s field carriage.
Type	Autocannon
Place of origin	Sweden
Service history
In service	1952 – present
Used by	See Users
Wars	Six-Day War Yom Kippur War Falklands War Iran–Iraq War Yugoslav Wars Russian invasion of Ukraine
Production history
Designer	AB Bofors
Designed	1946 – 1950
Manufacturer	AB Bofors > BAE Systems AB Breda > OTO Melara
Produced	1947–present
No. built	Over 5,000
Variants	Several
Specifications
Mass	2,400 kg (5,300 lb) – gun 4,800 kg (10,600 lb) – gun & field carriage
Length	≈4,000 mm (13 ft 1 in) for most variants
Barrel length	2,800 mm (9 ft 2 in) – barrel 3,245 mm (10 ft 7.8 in) – barrel, breach & flash hider
Cartridge	40 × 365 mm R
Cartridge weight	0.96 kg (2.1 lb)
Caliber	40 mm L/70
Rate of fire	240, 300, 330 rounds/min
Muzzle velocity	≈1,000 m/s (3,300 ft/s) for most shells
Maximum firing range	12,500 m (41,000 ft)
Feed system	16–26 round hopper
References	Bofors 1958,[1] Bofors 350 år,[2] navweaps.com[3]

The Bofors 40 mm Automatic Gun L/70,^[1] (Bofors 40 mm L/70, Bofors 40 mm/70, Bofors 40/70 and the like), is a multi-purpose autocannon developed by the Swedish arms manufacturer AB Bofors (today BAE Systems Bofors) during the second half of the 1940s as a modern replacement for their extremely successful World War II-era Bofors 40 mm L/60 gun-design. It was initially intended as a dedicated anti-aircraft weapon, being sold as Bofors 40 mm Automatic A.A. Gun L/70, but has since its conception been redeveloped into a dedicated multi-purpose weapon capable of firing both sabot projectiles and programmable ammunition. The Bofors 40 mm L/70 design never achieved the same popularity and historical status as the original L/60 design but has still seen great export and popularity to this day, having been adopted by around 40 different nations and even being accepted as NATO-standard in November 1953.^[4] It is still being produced and sold (since March 2005 by BAE Systems AB), and several variants exist for both field and naval applications. A notable variant is the Bofors 40/70B "light armored vehicle variant" which is in use on the Swedish Strf 9040 and Korean K21 infantry fighting vehicles.^[5]

The Bofors 40 mm L/70, like most Bofors autocannons, is based on the same core action as the original Bofors 40 mm Automatic Gun L/60, basically being a fire on closing, self-ejecting gun with a recoil-operated autoloader in the same receiver, and thus looks visually similar. Despite this, the Bofors 40 mm L/70 is a separate design with a number of major changes compared to its predecessor. The most superficial changes are the longer L/70 barrel, double cooling vents on the jacket and the fact that the weapon comes chambered for a more powerful 40×365mmR cartridge (vs 40×311mmR for the Bofors 40 mm L/60).^[4] Most importantly however is the new ejection system which ejects the empty cartridge cases out from the opposite side to the feed, compared to the ejecting system on the 40 mm L/60 which ejects the cases straight out the back of the gun. This system change almost doubled the mechanical rate of fire from the previous system.^[4]

In spite of the Bofors 40 mm L/70 being a separate development to the older Bofors 40 mm L/60 design, the similarities and success between the two guns has caused them both to be widely known simply as "the Bofors" or the "Bofors 40 mm gun", which at times causes the guns to be confused as one and the same weapon.