Go to Welcome To Buffalo Arms Co.
They have everything that you will need. Before you order any bullets you need to slug your bore to see what size you will need. Those old rifles in 44-77 come with a wide verity of bore sizes. Most measure over .450 . The SPG Lubricants BP Cartridge Reloading Primer,(If you do not have one you need to get one.) says that a very soft cast .446 bullet will bump up from the explosion of black powder and still give good accuracy. They list a load consisting of a Ballard Custom 414 grain 1-40 tin/lead alloy bullet sized .446 inch lubed with SPG lube with 75 grs. FFg powder. Winchester LR Magnum primer, a .030 thick card wad cut from tablet backing, (I would use a .030 Walters fiber wad that you can by a 1000 at a time) place the wad on top of the powder and compress the load about 10 thousands of an inch and seat the bullet to the wad. They give 2.875 OAL for this round. Velocity 1.344 fps from an Original Sharps, 30 inch barrel with 20 inch twist.
Until the 45-70 was introduced, the 44-77 was the most popular caliber chambered in Sharps rifles. It was first offered in the Remington Rolling Block and Sharps New Model 1869. Quite a few Creedmoor style rifles by both companies were made in 44-77 caliber, so it is entirely adequate even for 1,000 yard target shooting. Countless buffalo were killed with 44-77's, so it can be rated as a fine big game round. So have fun with that old smoke poll.