Hello, I have a 6mm X30-30 AI Iv'e been working up loads for. I've found Ackley's data was way to hot for my gun (Contender G2) . This Caliber is similar to the 6mm-225 just not quite apples to apples. Ackley's book #2 has the 6mm-225 in it. The 6-225 velocities seem high but they shot it with a 26" barrel. His velocities and loads were close to being on par with what I was finding when I reduced the velocity for barrel length (20" barrel, 25 FPS @inch) my velocities were 27-2800 FPS and I was using Varget and H4895. I was going to get a 6mm-225 before I got the 6mmx30-30 but I could never come up with any 225 brass. Hopes this helps.