Its a rocket propelled shell, should have little to no overpressure, it should however have some MODERATE backblast.
- Reproducable without other mods?
I'm pretty sure this is an ACE bug rather than CUP. Their overpressure/backblast system goes of off the same config entries, but adds a different eventhandler for both. "ace_firedPlayer" event for backblast and "ace_firedPlayerVehicle" for overpressure. Any launcher with the relevant config entries like the SPG while mounted on a vehicle will exhibit overpressure rather than backblast.
Looking at the config it appears to inherit from the 2A28 BMP-1 cannon, which in turn inherits from the D10 T-55 cannon, which inherits from the 125mm cannon of the T-100, so a bit of inheritance weirdness.
Would probably be better to inherit from the SPG-9 added by the Tanks DLC.
See line 2769 in CUP_Weapons_VehicleWeapons\cfgWeapons.h
strongly against the above, the backblast/overpressure is a single config entry, changing base classes like that is probably going to break a whole bunch of other stuff (which i definitely would like not to have to spend more time fixing).
will take a look in a couple weeks.