Here is a modified version of Traveller T20's autofire rule. Spend a variable number of shots (dependent on the weapon for real guns; up to your initiator level multiplied by two for the initiator strike) and a full round action, pick a 90-degree cone out to a single range increment of your weapon. Discard half the shots spent and make one attack against each enemy in the area, up to the number of shots left. If you have any shots left over, until the start of your next turn, each time an enemy enters the area covered you may make an attack roll against that enemy.
This doesn't sound very effective here. A high-level enemy isn't likely to fear a single mundane arrow-shot, even with an enhancing stance.
It's a shame because this sounds like a good real-world description. In the real world, however, one shot can kill.
Originally Posted by Ashtagon
Blot out the Sun (Strike): Your arrow acts as a dispel magic effect against any spell or magical effect with the light descriptor that is centred on the target that is hit. Your initiator level is treated as a caster level for the purposes of this effect.
Good name, but the actual behavior isn't iron rainish.