The Challenger 2/1 is
not the experimental Challenger Lethality Improvement Programme prototype currently under evaluation.
There are 1 or 2 trials prototypes of this, but no decision to go for it (and funding for CLIP has been withdrawn
Janes article ).
In any case - the 120mm smoothbore gun
can fire what is in game terms "HE", if such has been fielded by the user or developed as such. STAFF, MPATS and so on, Sweden apparently has one made from a 120mm mortar round.
Cheers
Andy