Thorn is not from charlamagnes vault, it's either a random drop or from an exotic weapon bounty. And second I did the bounty and have thorn. I'm finding it very hard to love the gun. I am putting my daily and material exchange xp into it each day and am half way through leveling the pierce and dot mod. However as it stands it's slow, inaccurate, terrible to reload and from the fps view looks like the pistol from Marathon. If the dot ticks like a hunters flame grenade I'll love it however I've yet to see it. Anyway end of rant TLDR: it's not from charlamagnes it's from a bounty.