Explosives Expert #2 Challenge only counts frag grenades

As of the 1.1.1.0 patch, I was finally able to complete this Challenge (and also the 3rd requiring 30 kills in a round) as the gunner of an IFV equipped with the grenade launcher turret. 

So the explosives of the IFV grenade launcher gunner count towards this. I'm not sure if that's always been the case, or if the general issue of certain explosives not qualifying has been resolved.