Better late than never. Yes I have tried IMR White hots in my Knight original disc rifle today (pellet cross-fire breech plug installed). Range weather sunny 27 degrees. IMR white Hots 2 pellets, Remington STS primer, Harvester Scorpion PT Gold 260 grain. 3-9 Bushnell Scopechief sighted in dead on at 100 yards 4 shots cut the same hole and two flinch flyers just outside the cluster group. Second group fired two more shots cut one big hole. 50 yard verfication with 100 yard zero point of impact approximately inch high. Impressed with the accuracy of the load combination to say the least. This rifle never shot like this before. Only complaint the stuff is just as dirty as 777 pellets. Swabbed between each shot for consistancy. Fired 15 shots total and it was a real chore cleaning the rifle afterwards. As with 777, the breech plug was getting tight at that point. But can't complain with the accuracy. This will be my hunting load in future for sure.