My 460 experience
My son has the same barrel length you do and we have been loading for it over a year or so now. We have used exclusively H110 / 296 with the exception of some gallery loads with Trailboss. We have loaded both the 240 and 300 grain XTP bullets as well as 335 and 395 grain WFN-GC from Cast Performance. Loads were out of the current Lyman manual and we settled on loads halfway between the starting and maximum. We got flattened primers at or near the maximum loads using WLRM primers although extraction was normal. The cartridge has enough power that there is no need to push it, so we backed off.
He took it to Alaska on a moose hunt last fall and carried it in a chest holster for bear protection with 395 grain bullets. These LBT style gas-checked lead bullets don't lead the barrel, and will kill game just as well as the more expensive Hornady jacketed. We found out how effective the LBT style bullets are, when his companion on the moose hunt had his rifle malfunction and killed a large bull with his Super Blackhawk 44 magnum with a 300 grain LBT WFN-GC at 15 yards. He shot it twice and it collapsed, then put two more in for insurance. He said the first bullet would have done the job, that it went through the lung and the liver and kept going to the hide on the far side. He's a veterinarian so I believe his assessment is correct.
If a 44 magnum will do that, the 460 will do even more. So if you plan to hunt, I suggest the LBT bullets. They're killers, but not meat wasters. If you just shoot for fun, either type will work. Recoil with all of them is manageable, but the 395 grain loads tend to hurt a little.
If you shoot at the range, give the guys on either side a heads up before you shoot. They're loud and put out a shock wave you can feel. My son's gun has a muzzle brake and that's hard on anyone off to the side.
