I am wanting to try some .446 money bullets before I order a mould.  Does anyone have some I could buy.
Buffalo Arms and CopperHead Swaging has them (naked or wrapped) ... 
http://copperheadcustomswaging.com/_wsn/page3.html (Call them for the 446's)
One item you didn't mention is the powder: Original gunpowder or smokeless ... it does make a difference for the wrapped size of PP bullet based on the bore diameter of your rifle.  And if it is a Pedersoli '74 Sharps, their nominal factory bore diameter is 450 for the 45-70
Yes, PP bullets will shoot accurately in a Pedersoli Sharps as long as the reloaded round is prepared correctly.  All Pedersoli barrels are match grade