QUOTE(madtoilet @ Apr 6 2012, 03:12 PM)
but does the armor piercing mod apply the same bonuses as armour piercing ammo?
yes, and its called penetration mod. its best use with sniper rifle and carnifex (with high lvl), BUT theres a penalty for using penetration; u hv less dmg to unprotected enemy.
scenario: using mantis lvl 1, base dmg 760, equip with penetration mod lvl 1, no AP.
lvl 1 penetration gives -0.5x to unprotected but +0.25x to armored (if im not mistaken, but watever, just an example).
sooo.....to non-armored enemy, u do 750 * (-x0.5) => 750-375=375
equip with AP lvl1 (+10%), thats 375+10% = 412
to armored target, u do 750 * (+0.25) => 750 + 187 = 937
equip with AP lvl1 (+10%), dats ~1030
u can see the details
here