Mr. Cole
suggests a special rule for flexible armor in his Armor as Dice: if a bullet outmatches a kevlar vest by even just a little, the vest provides very little protection and barely slows the bullet down.
How would I model that with standard GURPS damage rules? Perhaps like that:
"If basic damage from piercing attack exceeds DR of flexible armor after applying armor divisors (if any), protection is further reduced: divide leftover DR by 4, round down".
Or maybe there's a better way?