http://www.phasers.net/noncanon/sttng-riotgn.htm
Type III Phaser Rifle ("Riot Gun")
Introduced: 2368
Specifications: 58 cm long, 1.6 L in volume; 1.1 kg (with Type II "Cobra" phaser attached)/33 cm long, 1.1 L in volume; 1 kg (without Type II "Cobra" phaser attached)
Description: Sometime around 2367 after the Battle of Wolf 359, Starfleet R&D explored the possibility of an Type III Phaser Rifle extension for the Type II "Cobra" phaser. When attached the phaser would fire a series of compact "O"-rings of phaser energy at a target at an incredible velocity. This would (in theory) be used against species such as the Borg who have the capability to reflect or even abosorb phaser energy.
Settings: 1-16
Duration/Energy: 1,250 charges.
Range: 5/40/80/160/+40 meters.
This my take on this unusual weapon...did this sorta out of fun.