Hi,

reaction fire is not working well. What happen:
Soldier with pistol (TUs for reaction fire: 4) wait for an alien appear. TUs leaved for reaction fire: 12.
An alien appear in range and start firing three rounds' shot from particle rifle - TUs it spend: 15.
How many times soldier should fire before alien start: 3×
How many times soldier fire in game before alien start: 1×

There is a part of console log for this situation. - information about each hit.

From another situation - there is reaction fire working well.
Soldier with shot gun watch hole in a power station and has enough TUs for firing 3×. There are three aliens appear in sequence. All of them died by single shot gun hit (special ammo) - not important for this bug.

What this mean?
Reaction fire for multiple targets is working well, but for single target is not.