Making the assumption that the bore's clean, the metal fits well and the wood's not cracked in load-bearing areas - your Model 1884 should prove to be a good shooter - especially with the Buffington rear sight.
The 1884's didn't see the harsher service that their earlier counterparts did, so they're generally in excellent shape.
Stay with factory loads - and smokeless is fine - otherwise, there are numerous 'cowboy' loads available.
Vaya,
Scouts Out!