Hey thanx Garry . So , just to be clear are the 76 mm guns been upgraded to 100mm , 130 mm or are they replacing the 76mm with news 100 mm , 130 mm guns ?
The corvettes that are the subject of this thread would have gotten an armament in Soviet times of a single 76mm gun and probably either two 30mm gatling turrets or perhaps a single turret and an SA-N-4 naval OSA equivalent and perhaps 4-6 large anti ship missiles like SS-N-22 Moskit.
Fitting a 100mm gun would have been out of the question because of the weight of the 100mm guns.
The Corvettes being made now will be fitted with 100mm guns that weigh about the same as the old 76mm gun but with a much heavier shell fired over much greater range, plus much more heavily armed in terms of other weapons and choices.
For instance the single UKSK launcher will allow it to carry 8 Onyx supersonic anti ship missiles, but could just as easily carry anti submarine missiles that deliver torpedoes to targets 40km away at mach 2.5, or land attack cruise missiles able to hit targets 2,500km away or any combination of these weapons.
They have developed new light weight 100mm and 130mm guns that are the weight of 76mm and 100mm guns respectively.
The new 152mm gun was developed with the Army and in the army it is entering service as the Koalition. It has an effective range of about 70km and has Glonass/laser guidance to allow precision targeting.