France has tested a 140mm gun I think we should go for that for NGMBT.my confusion is Arjun mk2 still ongoing? I thought they ditched it and turned to 3 man crew unmanned turret NGMBT
The 140 mm caliber gun was tested by many NATO members like France and Germany in the 90s itself, as a result of intelligence report in late 80sthat USSR was developing a 152 mm gun to be mounted in their next generation MBTs. But it was not fielded by NATO since Russia choose to continue with their 125 mm caliber.
Arjun mk 2 project was conceived to resigned the hull and turret structure of Arjun MK1. The project was approved in 2016-17. The arjun mk2 was required to have 120 mm smoothbore gun and missile firing capability. It was decided that as stop gap 118 MK1A would be ordered till mk2 is fully developed and tested.
The FMBT project OTOH was initiated in 2010-11 itself, without any firm GSQR by the Army. Based on the Army's preferences, DRDO decided that the tank should be around 50 tons, have 3 man crew with 125 mm gun coupled to a autoloader. The project was progressing without any army involment.
After 2015, Army suddenly took interest Armata and in 2017 it launched a global RFI programme for FRCV wherein many foreign tank designers would competer against each other. And Army will choose the winning design and own the IP. This FRCV programme failed as no global manufacturer wanted to share IP.
DRDO taking a hint at the turn of events, morphed the FMBT programme into a Armata style crewless 50 tank tank programme around 2018.
Currently, DRDO wants at least 250 Arjun mk2 to be ordered after 118 mk1A, so that total production run is in around 500. Thereafter it wants GNMBT to be the army's replacement for T-72s.