This is a real diamond in the rough. A great weapon for an MR 7 that holds up pretty damn well and keeps them healed to boot.

Assuming all pellets hit, you have a cumulative probably of 99.93% that at least something will proc, a 99.26% chance TWO things will proc, a 96.33% chance THREE things will proc.....

Well you get the idea, this will proc a big stack of corrosive and fire, etc. which will melt the armor of whatever you're shooting. 80% of the armor will be gone from 10 corrosive stacks and 50% more of it will be gone after they're on fire for 2 seconds, resulting in the enemy having only 10% of their armor left to deal with at that moment. If said enemy has ferrite armor, then you also ignore 75% of the armor left and only have to deal with only 2.5% of their armor with your corrosive damage. So yeah, good against grineer.

As a reminder, the Justice effect from [Shattering Justice] does the following:
1) Does 1000 blast damage to all enemies within 25m, stunning them and reducing their accuracy for 6 seconds. (meh)
2) Heals you by 25% (Great for new players without access to self healing!)
3) Base armor increased by 15% for half a minute. (Meh. At best this provides a ~2% survivability boost for 30s)

A damn shame this thing does mostly impact damage, but whatever! This thing will hold up well through the star chart, although 5 forma and 2 primed mods will be off-putting for new players. Still, a decent and fun investment.

Why I do not use [Acid Shells]

I tried to like [Acid Shells] but it's just not worth it imo. If feels inconsistent, obstacles seem to block the AoE, it rarely feels like it actually goes 15m, and the damage is weak. It does 450 FLAT corrosive damage + 45% enemy health in BLAST damage. Blast damage is very shit as it's a mostly neutral element except against grineer, where it does -25% to ferrite armor AND is mitigated by an additional 25% of a target's ferrite armor. So that fat 45% health damage you'd expect against equally healthed grineer enemies around the grineer you just killed? It's now more like 1% to 30% depending on their armor. Absolutely abysmal.

[Acid Shells] would be a lot better if it did only corrosive damage, as a flat 450 corrosive damage is practically nothing.