I just checked on the latest PTR build and primal gore DoT crits seem to have a 1.5 base crit multiplier instead of the SimulationCraft assumed 2.0 multiplier.
In Cat DPS Spec, I get on a dummy with no RED meta:
rake Tick=2525 CritTick=3872
rip Tick=2444 CritTick=3594.
SimulationCraft predicts:
rake Tick=2486 CritTick=5640|5899|48.9%
rip Tick=2406 CritTick=5454|5591|49.4%
I didn't spend a lot of time testing so a second confirmation could be useful.
EDIT: I've done a second test without trying to maintain SR so just rip/rake/mangle unbuffed on a dummy and the results are more in line with what SC predicts.
Wow Web Stats
So base 2.0 multiplier seems ok, maybe I should upgrade my Recount on PTR