The build its actually simple. The new mod [Hata-Satya] caps at 500% critical chance. Every single shot from multishot counts as an extra hit, so ALMOST every shot its a guaranteed 2.4% increase. [Shred] adds PT and every enemy hit by the shots passing through an enemy again counts for the bonus, so if you hit 3 enemies with 6 shots (1 actual shot + multishot) its 7.2% critical chance. If you happen to be in a situation where you really need the damage, it ramps REALLY fasy because at a 7.2 ratio per round (and if enemies are high level, its actually way higher, you usually are hitting 5 or 6 enemies per round), you ramp to full 500% at arroumd 20 or 30 rounds. That leaves you with 500% added critical chance for the next 170 rounds. Its actually SUPER high damage, specially now that you have a constant 30% chance to trigger [Hunter Munitions], paired with viral, high rof and the relliable status chance it have, the weapon can [Shred] steel path enemies in less than 3 seconds.

The most important thing here is to LEAD YOUR SHOTS, dont just spray and pray. Agains high leveled enemies, make them align before spraying. This alone can get you into lvl 200 grounds with ease.

Quick QA: Why im not aiming at red crits? Because the way crit level scales. Going from non crit to regular crit (yellow) applies the critical damage multiplier on top of your damage. Here it is 6.6, so landing a yellow crit its a 660% damage increase. Landing an orange crit doubles the crit multiplier, so its 13.2, a 1320% damage increase, that means that going from yellow to orange crits its a 100% damage increase. Now, going to red crits, its a 19.8 multiplier. 1980% damage increase. Going from orange to red lvl 3 its a 50% damage increase. Investing into added critical rate at that point gives you less damage than adding a faction mod or even [Heavy Caliber] (82.5% damage increase). Unless you can get red crits without removing other impactfull mods, usually its always better to aim at orange crits and start investing into other stats :).