Clearly you haven’t done enough research.

Tap for spoiler

Use the railgun from Aquilo and shoot down the length so one shot penetrates multiple body segments

spoilerTank cannon shells have the same penetrative capabilities, are unlocked on Nauvis, and can easily be grinded up to uncommon and epic quality for that extra DMG. Haven’t tried them on big demolishers yet, so maybe they end up not being enough?

My tank gets destroyed before i can do any damage.

That happened to me at first as well. What made it feasible was to reconsider how I was approaching the fights

spoiler

literally: approaching a worm’s tail, while keeping the head as far away from me as possible, let me kill the worm before its cloud and eruption attacks ever reached me! Took about 4-5 rare uranium cannon shells to kill it in around 5 seconds, tops.