I would sell all the 454 stuff and use the money to buy components. Anything you can do with 454 you can do with the 460.

You are a reloader now. You can make 460 as hot or as light as you want.

Don't buy cheap commercial lead bullets and try to push them to 460 velocities. It will lead the bore. You will not like cleaning it out.

I would use 45 colt as a way to keep your light loads seperate. Also the cases are much cheaper. A quick look at starlines website shows 500 pcs. for around $90. Compared to around $240 for 500 460 cases.

If you look in your reloading manual you will see loads for the 45 colt that are pretty tame. If you want to juice them up look at the loads in 45colt t/c, ruger only part. There are some pretty stout loads listed in that section. They seperate them because older firearms can't handle the pressure. Your new 460 won't have a problem with them.

I am no expert on the erosion issue but I doubt light colt loads will hurt anything. I would think that you could run into a crud ring that builds up when shooting a short case. That crud can keep a 460 from chambering or make it hard to remove a case if you do manage to get it in. This is a fairly common thing for guys that shoot A LOT of 38 special in 357 guns. It can be cleaned out with brushes.

45 colt is a large case. It was developed originally for blackpowder use. With smokeless powder there is a lot of airspace when making up ligh loads with fast powder. Same goes for 460. Look into bulky powders like Trail Boss. Some others for midrange loads are hodgdon H4227, and Alliant 2400 . When you want all that gun has, H110/296 or lil' gun in 460 cases will give you what your looking for.

Hope this helps.