Few interesting details:
It looks like that the inside of the ST-1BR/ST3 is incredibly spacious from shots at 2:50 and 3:07, with even 4-6 chairs and a back door for infantry at the rear of the vehicle ? (or maybe the seats are just more confortable seating places for the gun crew during long range road trips). The turret interior also looks like the one of a SP artillery. The ST3 surpasses the Type-11 assault gun in ergonomy and versatility
-Still manual loading, no autoloader despite what looks like an ammo compartment at the rear of the turret
Does anyone know the max range of the ST3 in indirect fire mode ?