Don't throw out the .45 Super either. More than the 10mm, not quite a 460 Rowland. I load for it and I'm impressed with it for sure. The .45 Super and 460 Rowland don't really shine with .45 ACP designed bullets because they throw them too fast, possible exception being the 230gr XTP. Some .45 Colt revolver bullets work well in them, and IMHO that's where they shine.
I use a G4 G21 with KKM 4 port compensated barrel and a 22lb recoil spring assembly. The barrel with threading is right at 5" in length, and in the .45 Super I can load up 230gr JHP around 1,250 fps, a 250gr JHP (XTP or Speer Gold Dot) to around 1175 fps, or a big ole 275gr hardcast to 1150 fps which is 800 ft-lbs with an almost 300gr bullet. The same setup shoots regular .45 ACP just fine, but recoils a good bit less.
The 460R is a good idea, but unless you reload for it you're never going to get the ost out of it since shooting .45 ACP bullets 50%+ faster is just useless, your penetration is going to suffer. 10mm is okay, but I don't think it's quite to the level of potential the .45 Super and 460 Rowland offers. But if you have no intention of loading your own, maybe the 10mm is a better option for you, 10mm is expensive, but 460R ammo is a lot more pricey.
