What about something like the warrior deliverance/defiance. A different attachment for different situations

1.Breach-bore=40mm esque aoe damage dealing. Explosive shot for damage. Napalm cluster aoe with dot/slow. Willy pete blind maybe low damage?

2.Titanium lined barrel or rifled bore=(Similar to that of chrome lined barrels common in the majority of firearms today) Focuses on single target damage. Maybe something like a 3 skill combo with a buff (Magiteknical Rage) stacking every time you fail to get the additional effect for skills 2&3. Once X# of M.R. is reached next skill has increased potency? Something to mitigate RNG failure with an equally random potency bonus? Maybe the stacks of MR would have a passive effect.
>Each would be off the gcd and have unique skills.
> Combo using hot shot to self heal. Maybe cauderize wound? adenaline shot? Machinist feels like the guy with the gadgets for anything. i know the names are not well thought out.