RE: rapid fire artillery

“It was definately an artillery piece rather than a morter because of the simple fact that you see 3 shell casings ejected upwards torward the barrel. “

It is not actually that simple, the Russians have quite a few dual gun mortar systems that can fire mortar rounds and shells with cases.
Your description suggests that the weapon must have some sort of automatic feeding and clips are more likely than belts.
The 82mm Vasilek automatic mortar is rather old now and was used mostly by airborne troops as it was very mobile and had lots of firepower.
Perhaps this is a 152mm replacement?
A sort while ago at a defence expo in Asia the Russians showed a new light weight 152mm gun for highly mobile units.
Very little information was given about this system except that it was a light weight weapon for airborne units.
Perhaps they are one and the same or perhaps they were in competition for the same role.

I’ll have a look around.
Note it is not in “Russia’s Arms 2001-2002”, but then neither is the Vasilek…

Thanks for bringing it to my attention… 😉