Armor-Piercing ammunition and flexible armor

Recently I tried to study what AP ammunition for small arms actually is, and found out that some sources state that "hard core" ammo is designed mostly for piercing rigid (hard) armor, since projectile must deform in order to throw tungsten core forth.



Is it realistic for APHC ammo to have armor divisor against flexible armor? Are nylon and aramid fibers "hard" enough to let APHC do its job?

Armor-Piercing ammunition and flexible armor