Rheinmetall was lately in south africa testing ammunition for the PzH 2000.
The demonstration was for the aging DM121 Boattail replacement, the old ammo still in use does not use the full potential of the current PzH2000 system.
Rheinmetal offered three short term solution..
1. useing the already in service (Neatherlands) M1711 Basebleed ammunition. This ammo has a range of 40km
2. stronger powder ..the current pressure limit of the gun is 350MPa. This limit is not reached even with the 6th charge. Rheinmetal offers a 52 -23 Topcharge which increase the muzzel vilocity from 945m/s to 990m/s, this increase the range about 17% (during the life fire tests in south africa they even reached more)
3. M2005 V-LAP ammunition from Rheinmetall V-LAP = Velocity Enhanced Long Range Artillery Projectile... a basebleed ammo with rocket asist...
the combination of the existing gun the topcharge powder and the M2005 V-LAP was tested at sealevel and reached 66.943meter range..
The German Army wants for the future gun artillery with 75km and 100km range (50m accuracy at max range).
To achive this the German Army needs PGK Precision Guidance Kit for the ammunitions...this allows to adjust the ammo in flight ...drawback this system increase drag which decrease range.... to hit a target at 75km with a PGK guided ammo you need a range of 83km.
This is only possible with higher muzzel vilocity.
For that Rheinmetall design a new gun ...1,27m longer than the 155L52... the chamber volume increase from 23 to 29liter and the max pressure is increased to 500MPa.. the 155L66 ...
According to Rheinmetall the new gun can fire the ammunition to 75km (83km)
with precision ammunition are 155km possible
little sidenote in the article Germany increase the number of PzH 2000 from 81 to 108... and they are trying to get 108 wheeled version of the PzH2000 gun