Since you enjoyed the 460 Mag, Take a look at the 378 Weatherby Mag. It Ballistics are impressive. It shoots flat and fast and would iliminate the need to upgrade for a while. Soon someone will come up with a cartridge that will make the 378 look whimpy but until then you would be near to king of the hill. Speaking of 3100 fps, this puppy will do that with a 270 gr spire point. The 300 gr spire point moves along at 2900 fps. Cost wise the ammo should not be much more expensive than the two small rounds you are looking at. Check it out.