tips on how to quickly kill miros vultures?

[Brig Lig Smoke]

for spearmaster expeditions, they are tanky as hell

[RCMidas]

Any explosion to the face when they are over a death pit.

[Redlegoguy1]

For spearmaster's expedition mission my original plan was to use the singularity bomb from the perk, but then I DROPPED IT INTO A PIT before I could ever use it. For actually killing a miros, I basically just produced a ton of spears in a pile and then tried to get the attention of one, and then once I did I just pelted it repeatedly. Eventually I managed to brute force it that way.
As already mentioned though, bomb over a bottomless pit works pretty well, if you have the crafting perk that's also pretty easy to setup.

[NukMasta]

If you are an expert smuggler (or the Artificer, but I am assuming you are the Spearmaster here), an explosive spear does a good job