anywhere from 3-6 headshots on a level 80-100 Corrupted Heavy Gunner for the alt-fire shots.

What I'm finding is if you can get your crit to 100% and use Argon Scope (or the similar variant Proton Jet, if you don't have argon scope and don't mind wall-latching to get your crit chance.) you can get fairly consistent orange crits. You can also drop the status mods and put in [Hammer Shot] and [Critical Delay] and do the same roughly.

[Split Chamber], [Serration], [Point Strike], Vital Strike
[Argon Scope] (or [Proton Jet]), Hunter Munitions, Hammer Shot, Critical Delay.

Stats:
104.3% Crit Chance
7.0x Crit Damage
Fire Rate 1.92
Status 20.2%
IPS: 75.4 / 603.4 / 75.4

It's not bad, but I find it more useful for stealth missions honestly.

You can load this build-up with Zentih on [Banshee], or bring [Loki] with [Proton Jet] (for his extended wall latching). Then just start taking things out from rooms away easily as long as you fire while stealthed and run back to a safe distance.

--TL;DR --

• Argon Scope + Proton Jet are interchangeable
• Load your shots quickly into the enemy's head
• Try for 3-6 shots depending on enemy level (100 CHG = 5-6)
• Loki has extended wall-latch, which makes Proton Jet more useful
• If you can't afford Argon Scope, learn to wall-latch, it's not hard to get 4-6 shots off then re-latch.
• Use Banshee, or cloaking frames, to quickly take out enemies in other rooms. Toss-shot your alt-fire in, run back, and then scope them from afar.