I've had some very good success using 800X with 460 rowland. I've achieved higher velocities than anything yet published. I know that it's hard to meter 800X and maybe thats why it's not offered by any company.
that don't meter worth a hoot. A couple of years ago Mic McPherson posted on the old Sixgunner forum that some Canuck had run off with IMR's pressure testing equipment, and that (then) current batches of 800X were subject to dangerous pressure spikes in loads generating over 28,000 CUP (if memory serves). I never heard any other independent confirmation of this, and took it with a grain and a half of salt- but I was tired of trying to meter the stuff and looking for a better alternative anyhow. What I settled on was Hodgdon HS6.
HS6 will make decent light to moderate loads in straight-walled revolver cases, and does pretty well for heavy loads, too. My first hand experience with it is limited to the .357 & .44 Magnums, and I am just beginning to use it in .40 S&W. I am satisfied with it in all respects except one; it is a little dirtier than the faster powders like Universal and W231.
I am not aware of any published loads for HS6 in .460 Rowland.