The Fh-77 BD is a further development of the prototype system, which mounts the elevating mechanism of the earlier version, Fh-77B 155 mm towed artillery system on a commercial 6X6 articulated all-terrain chassis. This was originally developed as a private venture but was subsequently funded by the Swedish Defence Material Administration with two versions developed and tested by the Swedish Artillery School.
In March 2000 it was reported that the latest version of 155 mm Bofors guns would be sent to India for extensive field trials on “no-cost, no-commitment” basis in May 2000s. The Indian defence ministry accepted Bofors Weapons Systems’ offer to send the 45-calibre FH-77 BD, the towed version of which is already in use with the Indian army, for trials. India invited a number of companies to demonstrate their 155 mm artillery systems in a bid to finalise its choice to meet the army’s requirement of about 200 more field howitzers. The FH-77 BD 6x6 self-propelled artillery system and French Giat Industries Caesar 6x6 155mm 52-calibre systems are seen as possible alternatives to the towed weapon systems. Compared with conventional full-tracked self-propelled artillery systems, these weapons would be cheaper to procure and maintain and offer greater strategic mobility.
In early October 2001 it was reported that the Indian government wanted to buy around 3,000 additional FH-77 howitzers. A self-propelled artillery competition -- pitting the Celsius (Bofors) FH-77AD against the Denel LIW T-6 is underway as part of its Field Artillery Rationalization Plan. The main advantages that the Celsius FH-77AD offers over the Denel T-6 is that it is based on a proven and easy to maintain 6X6 Volvo truck chassis. The Arjun tank chassis to be used by the Denel T-6, in contrast, has yet to enter full service.
The FH 77B is able to fire 8 rounds and move 500 m away taking less than 3 minutes. It is also able to fire 3 rounds within 3 minutes and sustain a rate of fire of 8 rounds/minute. The system is provided with its own navigation system to achieve optimized accuracy performing multi-round simultaneous impact. The gun crew is transported in an armored cabin and the ammunition boxes have the same degree of protection of the as the crew compartment. A single FH 77BD carries 24 rounds and 42 charges.
The FH77 B is now integrated with a 6x6 all-terrain vehicle making it an extremely powerful, highly mobile artillery system. It's into-action time is less than 50 s. An artillery sequence: into action; fire 8 rounds; out of action and move 500 m takes less than 3 minutes. The gun has a range of 30 km, it can fire 3 rounds within 13 s and a has sustained rate of fire of 8 rounds/minute. On the move the gun crew is transported in an armoured cabin. The on-mount ammunition boxes, in effect magazines, have the same level of protection as the crew compartment. The FH77 B has its own land navigation system, eliminating surveying and alignment and the complete system has very low LCC.