So i was using barrage while killing goraks, obv pretty bored and i start looking my runes and i notice somth weird.. it doesnt always cost any barrage runes to shoot barrage

idk why is that, sometimes u can hit like 3 times before it tooks runes, sometimes 1 times..
and other thing.. while i was shooting nechryeals with barrage death spawns didnt spawn when the nechryeals couldnt att me.