[quote]Objectively speaking, Hawkmoon is better than Thorn in every stat except rate of fire. Seriously, it's pretty much a freak of nature with those imbalanced base stats. All handcannons have the same base raw dps(damage/RoF), but both Thorn and Hawkmoon have barrel impact upgrades which let them go above that, so they're kinda tied. But, Hawkmoon has the highest base stat values for every side stat except range, where it loses out to Fatebringer by a very slim margin.
For the perks, Hawkmoon has Hammer Forged, Speed Reload and Quickdraw as well as 2 perks that give it a total of 3 lucky rounds that deal 33% bonus damage.
Thorn has perfect balance, snapshot and send it in addition to final round and its famous DoT and overpenetration.
Let's say we're dealing with a high hp single target. While Thorn's DoT means that it packs more punch in a single normal shot, it doesn't stack so it's more like there's a persistent DoT throughout the duration you're hitting the target. The average reload speed and magazine size of Thorn coupled with Thorn being in the fast firing handcannon archetype unfortunately deals a great blow to thorn's effective dps. It empties its clip faster due to high RoF, so the time spent reloading is high in proportion to the time spent shooting.
Hawkmoon has the largest HC magazine size in the game at 13 rounds and a ugh reload speed, so there's less reloading to be done. Additionally, the time spent reloading can be further cut down with speed reload, increasing the time you spend shooting instead of reloading and improving effective dps.
From experience I'd say that the Hawkmoon's larger magazine size, lucky rounds and faster reload grant it greater dps output than Thorn with its DoT.
For mobs of enemies it's a toss-up. Thorn's overpenetrating rounds are definitely useful against bunched up enemies, but Hawkmoon's larger mag size lets it sustain a longer chain of kills.
I'd say that both are great in pve, but Hawkmoon is better [u]overall[/u] than Thorn as it is a better general purpose weapon. Of course, that doesn't mean that Hawkmoon should always be used over Thorn. In the first CE stage for instance, I find thorn more useful for its overpenetration against the huge thrall horde, giving 2 kills for every of Hawkmoon's kills. Regrettably I missed Xur when he sold the Hawkmoon upgrade, so I can't comment on whether both handcannons are able to one shot thrall maxed out[/quote]
Also, I'd like to add that attainability isn't a good factor to rank weapons with. Otherwise we'd just be ranking green weapons better than legendaries in crucible.