You can't explain that. – Periodically fires additional rounds of shock or corrosive. Bullets ricochet once.
Usage & Description
The Tsunami is a great submachine gun for usage against shielded or armored enemies, as the weapon specializes in destroying either one. The Tsunami is best used on Amara specializing in elemental damage, as she can take advantage of the weapon's shock and corrosive damage to great effect.
The Tsunami is a returning gun from Borderlands but as a legendary weapon instead of pearlescent.