Collateral Damage: Reduces the mana cost of
Iron Sights by 20. Iron Sights deals 50% bonus damage to minions, mercenaries and monsters.
Serious Kickback: Increase the width of
Coach Blast by 30%, as well as Ashe's displacement distance.
Reward: After hitting 15 heroes with
Coach Blast, reduce its cooldown by 3 seconds.
Boom County: Hit 30 heroes with Dynamite.
Reward: After hitting 10 heroes with Dynamite, increase the cast range of Dynamite by 35%.
Reward: After hitting 20 heroes with Dynamite, increase the blast radius of Dynamite by 20%.
Reward: After hitting 30 heroes with Dynamite, Dynamite leaves a series of explosives in its trail, exploding after 0.5s for 124(+4%) damage.
Perhaps an auto-attack armor shred to match the other two, similar to Hanzo's level 7 talent?
Iron sights also has a very high mana cost without taking the level 1 upgrade to the point of it being punishing to use it at all--Secondly,
Does her I.S. usage draw from that same ammo pool that I would assume her auto attacks consume from? If so/secondarily, is it a skillshot or a directed line-nuke like Alarak's E?
Otherwise seems pretty good overall! I would personally advocate for some kind of fast reload option at either some point in her kit or as a big upgrade, especially if she consumes the shots for auto-attacks. You may want to lower her range to 6.5 though, to be on par with say, Nova, as she already does 40 more damage than her baseline with the same attack speed. Even as reliant as Ashe seems to be on her auto attacks, that's a substantial increase later on with the 4% (or more with talents) kicking in every level, even having to reload. (Edit: The ammo system question makes me wonder if you'd seen my Pharah concept, as I had a similar system there you might find interesting.)