I have too many loads to list that will work, do you plan on shooting saboted bullets or conicals? Most any Black Powder (Goex, Swiss) or BP Substitute (Pyrodex, Triple Se7en loose powder) in the 80gr to 100gr range will shoot most any bullet in the recommended loads range. Saboted bullets in the 200gr to 300gr range do well with 85gr to 100gr of powder or 100gr of Pyrodex Pellets. I do not recommend Triple Se7en Pellets with the OEM breech plug, they are not 100% reliable in my 3 rifles with the primer carriers.
If you wish to shoot conicals, 80gr to 90gr of loose powder and a 400gr to 480gr pure lead conical will do very well. I prefer the 440gr conicals for a .50 caliber with 1:28 twist. Another conical that shoots the best in my rifles is the 350gr Hornady FPB, with 80gr to 100gr of powder.
One thing I would recommend is getting a good range rod for loading and cleaning, and only using the OEM ramrod for loading a follow up in the field. If you want to shoot Blackhorn 209 powder, there is only one reliable breech plug option other than a custom breech plug. The OEM breech plug is not even slightly reliable for that powder.
Let me know what type of bullet you want to shoot, and I can give you some specific load information.