This was originally a meme build, but since this thing hits like a freight train I've optimized it more for actual use.

• Update for 1999: Primary Acuity is nuts and massively outdamages Galvanized Chamber even with other CC mods
• If you have a good crit (especially CD for Primary Acuity) or elem/IPS Riven I would recommend swapping [Bladed Rounds] for it. You'll need an extra forma to fit it, but the increase in damage will (probably) be worth it. For reference, my riven with +heat, +cc, +cd, and -sc makes this deal around 50% more damage overall per hit when taking the place of Bladed Rounds.
• If you don't have a companion for priming (or any other method, but a companion is probably the most convenient for this outside of relying on allies priming for you), switch Galvanized Aptitude for a crit or base dmg mod.
• Exilus mod is up to preference
• You can swap Primary Deadhead for Primary Merciless, but you'd be trading much faster stacks, far longer stack duration, increased headshot damage multiplier, and halved recoil for not having to hit headshots to stack (which is kind of pointless since you should be hitting headshots anyways) and a small reload speed increase. In other words, use Deadhead.

(not to be confused with the [Lanka], which is an actual handheld railgun)