uhhhh... not sure what you mean dude.
2S19 and 2S5 fire the same ammo, and have practically the same range. 2S5 is mostly a cheaper artillery system, while 2S19 is more recent and totally enclosed, much more armored, much more automated. The 2S19 is intended for armored troops mostly, following tanks in all kinds of environement, while the 2S5 is a classic long range artillery.
2S5 has a slightly longer barrel and maybe higher pressure tolerance, but ammo are strictly the same.
2S3 however fire the same ammo too, but only limited to a smaller charge load than bigger systems (smaller load of propellant for the same case pattern I think)...
Or am I totally wrong? In fact I think 2S3 and thus the D-20 howitzer, both use the WW2 (infact pre WW2) pattern cartridge, as used in ML-20, D-1 or ISU-152 systems.... while the Msta and Giatsint systems both use a newly developped case pattern, bigger.
Koalitsya will use the same pattern ammo, or a brand new 3rd generation 152mm case?
As far as I know, we can say 152mm systems are in two category:
SU / ISU-152
2S3 , are all "medium" power and range weapons, reaching 15-18km with standard ammo (much less for D-1 small howitzer)
2S19, are a level above, usually reaching 28-30km with standard ammo.
Question is, where is Koalitsya? Judging by new gun, longer, higher pressure tolerance, and possibly new type of propellant for the cartridge (while retaining case pattern of 2S19 and having the ability to use old surplus ammo), i'd say 32 or 33km as standard is expectable, and if a new cartridge comes with it, somewhere between 35-40km