"Pride of a Nation; a beast made of steel!"
I made this [Zarr] guide because I saw all these scrub builds for the [Zarr] and none that displayed the true might.
I love the [Zarr] and it's without a doubt my first weapon to truly adopt as my own among my crew of friends. I am seen as the "authority figure" on the topic of this weapon and get asked a lot of questions about it.
It is a reliable weapon that is useful in almost every mission (including Stealth missions.)
To make it short and sweet.
When do you NOT use this weapon?: Assassination missions
Don't take my word for it, instead try to run an assassination mission (or all of them) and see how (in)effective this weapon is under those circumstances.
What role does this weapon serve?: Artillery
this weapon is meant to bomb the ever living crap out of your enemies. If you're not continuously bombarding your enemies with shells, you're doing it wrong. This weapon is meant to be fired all day, every day, every minute of every hour. In fact, just to keep my accuracy acute and enemies at bay, I will fire this weapon randomly to experiment and observe it's cluster pattern.
Why would I get this weapon?: Because Verdun.
Verdun is known for the massive battle that took place during World [War] 1 where the French Forts of Verdun had undergone almost a whole year of constant artillery bombardment from the German army. Dozens of soldiers were not yet prepared for the horrors of modern [War] and to everyone's surprise (including the French) their forts with stood the absolute abuse of German artillery though several did fall prey to constant barrages. The [Zarr] is a weapon that captures the spirit of domination through suppression, hence my bit above where I said "Must be fired all day." the German General Chief of Staff Erich von Falkenhayn's plan was to "bleed the French army" by forcing them to reinforce the forts at Verdun essentially making the French defend positions that inevitably were going to be struck and exponentially increase French casualties.
Bleed the Grineer, Corpus, Corrupted, and even Sentient with the [Zarr]. Strike with the force of a thousand guns.