I have a .460 Rowland in both 1911 pistol form with compensator and a .460 carbine with a 15 inch barrel. I only shoot reloads using either Longshot or Accurate #7 always with Nosler 230 grain hollow point bullets and CCI pistol primers. The pistol produces velocities right at 1300 fps. The carbine produces velocities of 1500 fps. When I look at burning rates of the two powders, #7 is rated faster than Longshot. But when I look up loading data, more #7 by weight is recommended than Longshot. I have also experienced higher pressures with Longshot at the same loading weight. In the carbine I can only use 12.6 grains of Longshot but use 14.6 grains of #7. That is significant. Velocities are about the same with either but #7 gives my carbine better groups so that is what I use. Can anyone explain this? Are burning rate charts in error?