pistol takedown not working

[Adden]

When I start to do a takedown it pops up with an icon of the right mouse button. I've tried clicking it during the takedown and holding it down. I've tried holding it down before starting the takedown, it won't do it. I have my pistol out but I just do a melee takedown.

[Thierrymon]

Yeah, same issue here. The challenge has me down as 3/5 in pistol takedowns but I have no idea how I did them. Following the prompts either isnt clear or not working properly.

[Myraddin]

same here

[Dramavian]

The game doesn't make it very clear. It took me a good few hours to discover what it actually does after unlocking it.

Sidearm takedown is actually a ranged chain takedown.

Press F to takedown your first target.
If the prompt appears hold down right-click to whip out your pistol (or melee weapon if you don't have a sidearm).
You will then quickly aim at the nearest enemy in line of sight. (Range seems to be slightly more than effective shotgun range)
As soon as you see the new prompt appear by the new target press left+click to either fire your gun or chuck a melee weapon at their head.

This seems to always result in a one-hit kill, no matter the enemy type. (Armored guys, flame throwers, VIPs, etc).

[Manticore]

Any necromancers around? I do exactly as it says but it just doesn't work. The gun will shoot just randomly in the air.