Vampiric Burst adding more ammo after finishing Venator's ult

[AnhDoo]

This bug let Vampiric Burst stacking your ammo into a ridiculous amount like in the picture below

Precondition to recreate bug:
1. Play as Venator
2. Buy Vampiric Burst
3. Toggle fast cooldown and stamina (Optional)

Steps to recreate bug:
1. Use Ira Domini (Venator's ult)
2. Shoot until the ammo runs out
3. Use Vampiric Burst
4. Extra ammo added