This is my Regulator Builds for my [Mesa Prime] Build below
Mesa Prime Build

This is a Standard Corrosive Build for Secondaries

Multishot with [Lethal Torrent] and [Barrel Diffusion].

Damage with [Hornet Strike].

Corrosive with [Pathogen Rounds] and [Convulsion]

[Target Cracker] and [Pistol Gambit] for CC and CD. You can replace these with the primed version if you have them but it might require a forma.

[Anemic Agility] slightly reduces Damage but massively increases Fire Rate.

With Rank 5 Arcane Velocity from the [Mesa] Build you have 220% fire rate for over 50 bullets a second.

With Arcanes active you can get up to 500k sustained Damage