Melta Cannons

Gentlemen, I have some questions regarding this strange weapon that you can find mounted on the Devil Dog variant of the Hellhound Flame Tank.

As its name implies it is a range 24 inches blast weapon with melta rules.

The question is whether i will get the additional D6 when firing at a target within 12 inches or do i measure again after the scatter has been rolled to see if i get the additional D6?

After looking through some other forums such as warseer their opinions are also divided.

Your thoughts gentlemen?

You always get the additional D6, except against certain weird xenos stuff. That's the beauty of it. It works more like a meltabomb then a meltagun or multimelta.

i always thought it still subject to the melta rule. you only get the additional D6 if the target is within half of the weapon's range?

special rules bro... special rules... exception to the regular rules.

This is how i would do it...

say a devil dog is firing on a land raider.

Place the marker first.
Roll scatter die and 2D6.
Place the marker's final location.
If the marker is still on top of the land raider and within 12inches of the devil dog, then you get the extra D6. If not, then there's no extra D6

Without knowing the exact wording of the Melta Cannon, I think it works just like other Melta weapons and resolve as how Dann described it.