Two Tictacs and an Armour Piercing Bullet

You bring into existence 1 armour piercing bullet and fire it at a target. The target of the spell must make a DC15 DEX saving throw or be hit by a metal shard that ignore resistance and rips through armour if it weren't there at all.

On a failed save the target takes 1d10 force damage, and additional 1d10 piercing damage.

Why the tictacs are important to this spell is unclear but then again why do you need bat guano for fireball....