Bioimmunity grants the ability to choose your best save and Total Immunity treats Ammo like Normal Ammo. However, "Normal" no longer means you take a save against ARM, it means you make a save and lose a Wound/STR. See Normal Ammo and see Saving Rolls If you look at the Nanopulser, it has the Normal Ammo trait and seperately the weapon refers to the relevant save attribute. Total Immunity changes any Ammo to Normal (and ignores traits) it does not, however, have any bearing on wich save attribute you use for the weapon because Total Immunity has no such wording.
Volkolak has no Vulnerability. I know it's obvious, but it can lead to some confusion for a new player
Yes I know. But the great thing to know is it's taking a BTS 0 save! Viral, breaker, nanopulsar, pulsar, e/m ccw, and plasma goes against BTS and cause a wound.