After the NATO standardization to 155mm artillery pieces, found by the West to be the best balance of range and firepower (the Soviets went the 152mm route instead), several national powers took to local solutions. For the Swedes, this became the FH77 "Haubits", a towed field howitzer introduced during 1978 and currently (2018) serving the armies of Sweden, Nigeria and India (and supposedly with Iran by way of Singapore). Between 1979 and 1984, the Swedish Army acquired around 220 examples of this fine artillery piece. India did them better and took on a stock of 410 units from 1986 to 1991 though only about 200 remain in service as of this writing (2018).
Design work on the FH77 was undertaken by the storied Swedish concern of Bofors in 1978 and production occurred quickly after trials and evaluations took place. The product showcases an overall weight of 25,400lb with a length of 38 feet and a width of 31.10 feet. The barrel measures 19.3 feet in length. The operating crew numbers between nine and fourteen personnel, each assigned to a specific task of the gun's function.
The weapon fires the standard NATO 155mm projectile in its various forms - High-Explosive (HE), illumination and smoke being typical. The projectiles are semi-fixed ammunition with the propellant charge held in a plastic case featuring a steel-based head. The gun's breech is accessed by a vertically-sliding breech mechanism and the projectiles rammed by a hydraulic ("flick rammer") component.
The carriage unit is a standard two-wheeled, split-trail system in which the tow arms double as the recoil supports when the weapon is made ready-to-fire. A dedicated recoil mechanism found under the barrel also aids in retarding some of the violent recoil forces at play. The barrel is further capped by a heavily-perforated muzzle brake for added recoil dampening. At the carriage section is also an Auxiliary Power Unit (APU) provided by Volvo and allowing the gunnery crew to relocate their weapon over short distances as needed (a Scania SBA111 mover vehicle - or similar - is typically used otherwise). The FH77 is notable as the first modern artillery piece to feature this quality (since copied globally).
The mounting hardware allows for an elevation span of -5 to +70 degrees to be reached. Traversal of the barrel from its mounting surface is 30 degrees left or right of centerline.
Performance of this battlefield piece includes an effective firing range out to 13 miles with a maximum range out to 15 miles using standard ammunition (non-rocket-assisted). The weapon can reach a rate-of-fire of four rounds per nine seconds and sustain three rounds-per-minute for up to twenty minutes. Muzzle velocity of each out-going round is up to 2,530 feet-per-second.
Since service introduction, the FH77 has appeared in two major production forms, the FH77A and the FH77B. The A-models represent the original Swedish Army production forms and feature a Volvo gasoline-fueled APU system as well as a /38 caliber barrel measurement. The B-models are the export version and these come with a Mercedes diesel-fueled APU system and a /39 caliber barrel measurement.
The B-model also serves as the primary gun of the FH77B "Archer" wheeled self-propelled artillery gun platform (detailed elsewhere on this site). These guns were leftover from forty-eight additional Indian FH77B units that were redirected to the Swedish Army following the Bofors Scandal involving Indian government officials.