Why do you say to run jacketed bullets at less than rated velocity? Kinda hard to stay withing load data and exceed the bullet makers max velocity from a revolver? Like Hornday bullets.
For clarification My statement should at or less
It is easy to exceed any of the XTP line of bullets and is possible to 240 XTP MAG also. The 225 FTX also is easily exceeded out of 460. The 250 FTX has no cannalure so is a poor choice even though it would probably stand up to 460 use. Yes I am talking about revolvers.
If you are shooting on of the few rifles models chambered in 460 most jacketed bullets design velocity will be exceeded. I personnel recommend monolithic designs out of rifles.
Bottom line it is possible to load many 45 calibers bullets well above their design velocity in a 460 case.
I've heard also not to use cast lead.
Nothing wrong with run cast lead out of a 460.
If you want to ensure you are not going to lead your barrel make sure your bullets are sized for your gun. Rather than discuss bullet fit here I would suggest individuals wanting more information go to the cast boolits forum where you can find endless discussions.