Ok, lets take a look at the perks on this gun, David and Goliath. While this could mean nothing, I think that these are symbolic perhaps of the way to acheive this gun. The name of the exotic gun, the 347 Vesta Dynasty, and its similarity to that of our little sidearm, the Vestian Dynasty, as well as the size of said pistol leads me to believe that this could be the David part of this equation of getting this exotic rifle. The Goliath part, I believe, is Skolas. Perhaps on an arc burn week in the future we'll see that people are getting this from defeating the Goliath with our David pistols. I have seen gameplay of people using only the Vestian Dynasty to defeat the Templar, Atheon, and Crota, so those are not possible enemies who will, when defeated, will drop this weapon. To defeat Skolas with only this sidearm is certainly a feat deserving of at least a chance for an exotic. Thoughts and opinions welcome.