The Mk6 Mortar, the M4 Scorcher, and the MRLS feature variable strength charges for differing ranges. The MK6 has Short, Medium, and Far, the MRLS has 4 settings ranging from Short to Full, and the M4 Scorcher has 5 settings from Short to Extreme. However, at the moment, there is no visual indicator that I have noticed for which type of charge is being used at a given time within the gunner or commander's seat.
This is a major problem for attempting indirect fire without using the artillery computer (which I find rather boring to use) on any target that the player does not have a line of sight on. The max theoretical range on the Scorcher is enormous, but if I've lost track of whether I'm on short, Far, or Extreme, any attempt I make to use a manually calculated firing solution will be a crapshoot as to if I even have the right fire mode set to cover that distance.
There should be a clear indicator in the ammo counter as to which mode is enabled. A rifle's zeroing and fire mode are constantly displayed in the ammo counter, having an artillery piece's fire mode (and possibly its applicable ranges) be displayed there for the gunner to take advantage of would be just as useful.