I can see something like that as heavy cruiser turret, or maybe in some GB forward gun slots.
It shouldn't be good from close range - so probably no proximity fuse, but then when it only explodes at max range I'm not sure if it does damage. Now if even it's made to work like that, then it can't do too much damage to avoid big number of instakills, so probably some 6-9k damage max, but then again will that really be useful in a fight?
Igiss says: Martin, you give them a finger, they bite off your arm.