IMR 4895 a "dirty" powder?

[Ken14]

Just picked up a pound of IMR 4895 to use in my .308. After 18 to 20 rounds whis is the norm for my load development sessions, I came back home and started to clean rifles. To my surprise the 4895 loads turn the patches MUCH blacker than the loads I use withe RE-15 or Varget...also seems to take more "elbow" grease to get the job done. Anyone else notice this ??