So let's jump right into it.

1) Make sure you have atleast 2 shotgun and 1 Sniper Rifle before taking on those tank enemies.
2) Quickly switch to another weapon before reloading. When you're on your last weapon,switch back to your strongest weapon and let it reload for a bit.

It is recommended to use a Purple-rarity weapon for these kind of stuff.
Tediore weapons are also recommended for these stuff. This is due to their high reload speed and the fact that it also works as a grenade.
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