I wanted some long range powerful secondary gun with automatic fire and this build was pretty successful, as much I used it.

It has extended magazine thanks to the [Ice Storm], as well as extended Ammo amount at all. But it uses increased fire rate thanks to [Lethal Torrent] and extra [Mag] capacity compensating this.

IMHO, don't afraid to use BLAST, but you may switch on VIRAL if you wish, as weapon does slash DMG. I even sometimes using Magnetic DMG on it, eg. for Nightwave achievements & so on.