John, Somebody might have more experience on this than I. All I can say is be careful loading below the listed starting loads in the manuals, especially with jacketed bullets. You want to use a powder that's specifically suited for reduced loads. These will usually keep a good loading density to be uniform. SPEER lists some reduced loads in their manual for the '06 using SR4759. Not sure if this powder is still available. Stick with approved data though. I'll do a little more research.