Talk:Corrosive Projection/@comment-24085284-20131202110029/@comment-92.85.172.141-20131214055222

Not quite. Armor bonuses work differently then the other elemental bonuses. Effectively, the % bonus towards armor counts as armor ignore. For example, 50% of Piercing dmg gets thru armor and will never be reduced below that, while 75% of corrosive dmg does the same.

The problem with Grineer is that at lvl50+ their armor is so high it can nearly mitigate most elements and you end up doing next to no dmg (still trying to find an exact number for lvl50 Grineer armor reduction, but I'd assume over 60% easy). Using Corrosive Projection aura and Corrosive dmg/Piercing dmg will largely mitigate this problem however. Couple those with mods that add base dmg/multishot/crit and crit dmg, and you should be doing enough to handle even the highest lvl Grineer.

As for OP's question: no. Unmoded Ignis deals pure Fire dmg, which in Dmg 2.3 doesn't recive any armor penetration - so it gets reduced by the armor value - whatever that may be for the Grineer you're shooting at.

However, a day before this post, Fire was actually dealing 75% of it's dmg streight thru armor, since it had a 75% modifier versus armor... but that was yesterday in Dmg 2.2. Basically both your friends are right, but one has outdated info from yesterday.