My own thoughts:

Immediately after tank hits, drop Bishop/Rook (Hypercharge). (Raging Strikes)(Blood For Blood) Hotshot (Hawkeye)(Dex Pot)->Lead Shot (Reload)(Wildfire)->Split Shot (Quick Reload)->Slug Shot (Reassemble)->Clean Shot (Quelling Strikes)->Split Shot (Blank)->Slug Shot ->Clean Shot->Gauss Barrel (Rapid Fire)->Split Shot (Gauss Round)->Slug Shot (Ricochet)->Clean Shot->Hot Shot->Lead Shot-~~~~~

Drop and hypercharge turret, buff up, Lead Shot and Wildfire. Reload/Quick Reload into two ammoed rounds of Split-Slug-Clean combo, Wildfire Proc. Weave in Blank and Suppressing Fire/Head Graze when appropriate to actually get use out of instead of merely using them for damage. I -think- you can drop into Gauss Barrel and still Rapid Fire out Split-Slug-Clean with no cast time before Hot Shot and Lead Shot expire, weaving in Gauss Round and Ricochet. After this, let your turret autoattack for you, re-up Hot Shot and Lead Shot, and just keep pounding out shots with Gauss.