I picked up some 180gr XTP projectiles in order to load some hot 10mm and see what I could get out of them. I have a couple pounds of 800-X, so I want to use that, besides, I heard it gives good velocities in 10mm. My problem is that I have conflicting data. My Lyman manual lists start and max charges of 6.8 and 8.4 grains, seated to 1.25", velocity of 1073 FPS (for 180gr JHP). I also have one of the LoadBook USA books, it gives start and max charges of 6.7 and 10.1 grains, seated to 1.26" giving a velocity of 1250 FPS (for 180gr XTP). So my question is, is Lyman publishing CYA data, or is the LoadBook data way out of the ballpark?