Stop a unit from firing

[Dutch Grenadier]

How can you make a unit stop firing on a target. I wasted all my mortar ammo on a single soldier.

Note: The mortar was on map in LOS with the soldier so it automaticly attacks.

Also a LMG keeps firing on a tank wasting its ammo.

Do you need to set an arc then to stop them?

 

[Bidermann]

The best way I have found is to set a cover arc less than the target so the unit wont fire

 

[Dutch Grenadier]

So you do need to set an arc.

 

[mTk]

Its as good a way as any.
"Hide" will (usually) keep a unit from firing as well.
In the "targeting" category there is a "clear target" button has always stopped units firing for me.
The only time I can think of when it might not would be dependent on the morale status of a unit that may temporarily not be taking orders of any kind.