I suggest the RCBS mould for a flat-nosed 440 to 460gr. bullet. Most of the Sharps copies have a 36" rifling twist, and will shoot this bullet well. You shouldn't need to size this bullet and should shoot it as cast. I suggest the rCBS mould rather than the Lyman 450gr. .515141 due to the Lyman bullet being quite pointed and lacks "punch" to the animal. It will work, but the RCBS is a better hunting bullet. The 36" twist isn't a very good rate of twist for 500gr. or heavier bullets, but some say they shoot well.
: www.trackofthewolf.com has brass, wads and other loading supplies such as lubricants and possibly moulds as well.
: If you can go to the Hodgdon web site you may find smokeless loads for the .50/90 Shaprs, as well as the Accurate Arms powder site. Both have good loads iwth a variety of smokeless powders.
: If you want to use black powder or one of the modern substitutes, a 90 to 95gr. charge, with very thin wad of paper or wax paper (to keep lubricant disk from spoiling the charge), then a lubricant disk about 1/8" thick, then card wad, then the lubricated bullet.
: Lyman, SPG and OxYoke all make very good black powder lubricants that shoot well.
: 60% beeswax and 40% valseline is an exceptional home made bullet lube for black powder. These all work well with smokeless powders too.
: If you have any difficulty, mail me at dtlc@telus.net I'd be happy to help in any way possible.