what is the salvo strike ability available at the crafting station?

BeerLord_0​ If you mean the "Heavyarms Salvo" Wildcard:

• Heavyarms Salvo: Marks enemies for air support missile strikes after landing multiple hits.

This means that as you hit enemy players, it builds up a target lock which would launch missiles at the player when fully locked on.

ive never noticed any target lock after shooting people but all right then

BeerLord_0​ It is hard to notice as it uses a cyan blue color, (which often blends into the player you are shooting at).