What rune makes Hungering Arrow do the most damage on average?
Shatter Shot has the best overall output.
The expected average damage outputs per use (calculated up to the 10th piercing) are:
- 177% for Hungering Arrow (base)
- 230% for Puncturing Arrow
- 231% for Cinder Arrow rune
- 301% for Shatter Shot rune
- 283% for Devouring Arrow rune (assuming each piercing does 170% damage of the previous one), or
- 235% for Devouring Arrow rune (assuming each piercing does an additional cumulative 70% base weapon damage)
You could see the breakdown on this document.
Note: The dual interpretation on the Devouring Arrow rune (multiplicative, i.e. the damage on the 3rd pierce is 1.7*1.7*BASE, or additive which would be (1.7+0.7)*BASE) comes from this other answer. The answer states that the additive interpretation is the correct one.
Spray of teeth is currently gimped. I've been running HA runed with SoT for a while, and the bone spray actually hits mobs with large hitboxes. This means that if assuming i'm fighting Azmodan, and Hungering arrow crits, i'll have dealt the initial HA damage crit + 50% bone Spray (which also crits) to him because his hitbox is so huge.
Furthermore, you're forgetting that Hungering arrow itself always have a 35% chance to pierce regardless of rune, so theoretically it's possible to crit with HA (triggering bone spray), and at the same time have it pierce the mob and come back round for a second possible crit (triggering another bone spray)
These are just based on my observations using that particular rune.
With an base damage of 100 (non fluctuating), counting the average puncturing chance with theoretically infinite possible punctures you would get the following numbers per shot:
Base: 176.9230769 dmg Puncturing: 230.0000000 dmg Cinder: 230.7692308 dmg Shatter: 300.7692308 dmg Hungering (each pierce is 170% dmg of the previous): 283.9506173 dmg Hungering (each pierce adds 70% of base weapon dmg): 261.9135802 dmg
So the definitive highest overall damage output is with Shattering shot, but since these numbers are purely statistical, and Shattering shot is highly situational (depends on number of enemies on screen), your best bet for single target is devouring arrow.
Did the math with the limit function.