I run about the same on all primary weapons: Scout: 45% - 13715 precision kills Hand Cannons: 42% - 3514 kills Auto: 42% - 3425 precision kills Pulse: 46% - 298 precision kills Thorn: 40% - 45 precision kills <-- Just got this weapon Funny thing is the Vex Mythoclast is listed as a Special but resides in the primary slot. For that one I have a 56% precision kill rate.