The damage on both ammo types of the 40mm canon are to low on soft targets and vehicles. The GPR-T round has no splash damage and will not even 1shot infantry if DIRECT hit (unless hs or throat) neither will it penetrate windshields of MRAPS (hunter or iffrit). Same issue is with the AP-rounds they also need multiple rounds on infantry but they actually penetrate MRAP windshields although the penetrating round is unable to kill passengers if hitting the head. Low damage performance is also given hitting engines and wheels on MRAPS with AP-rounds. 3 hits on engines with each GPR-T and AP could not kill the engine similar result on Tyres.
Edit: seems to be CBA check note 6