Amos, You're welcome!!! Sorry, I don't know when it will be available, but since Sports South lists it already, I'd hope it will be early next year as a rifle, accessory barrels usually follow the rifle's release by a month or 2.
Lik2hunt and Swampman, I don't know what the 460S&W's SAAAMI Map is, but the G&A link below says it's 65kpsi, 5kpsi more than the 500S&W, which makes the .500S&W 60kpsi, but all the load data I've see shows a max pressure of about 52kpsi, so I don't know what's up with the 8kpsi difference. None of the new cartridges are listed in the SAAMI charts at the link below. The Casull's SAAMI MAP is 50kcup, which using the conversion formula of (1.51586 * CUP) - 17902.0 = PSI, puts the Casull at about 58kpsi.
Tim
http://www.gunsandammomag.com/ga_handguns/sw460_072905/http://www.frfrogspad.com/miscellk.htm#pressure