First off, I see no rules for what exactly a hellgun capacitor does. Only the Cost, and the availability. It doesn't even weigh anything. I checked the errata but no change there.
Secondly, would rewriting the rules for the twin lasgun to be
Twin Lasgun Basic 100m -/2/6 1d10+3E 20 Full Unreliable
be unbalanced? I like that more than the tearing, and it'd be nice for my acolytes to have access to a full-auto lasgun