32-20 S&W pistol ammo

I have tried and failed finding information about the correct ammo for my gun. I have a early S&W pistol 32-20. I have found the the 32 of course is the caliber and the 20 stands for the amount of BP grains used for the load. The bullets I have been able to find are stamped 32-20 but I am sure they are loaded with smokeless powder since they are modern loads that have been around the last 50 years or so. The 32-20 was originally developed for both rifle and pistol as interchangeable loads and both were BP CTG. My question is fairly simple. Using modern reloading does and don't one should never load a pistol CTG with anything but a pistol primer. The bullet has to be a full lead bullet and the shell casing has to have a shoulder unlike the standard 32cal. Can anyone give advice whether a BP load 32-20 with a 80 to 110 grain bullet along with a pistol primer be the only safe CTG to use in these vintage guns. That being said is the older 32-20 rifles in the same situation having only BP loaded CTG's. My heaven when you begin to understand how different these guns were made and how different the ammo was at the time I really feel that modern smokeless power is gong to harm the guns let alone the shooter. Maybe the only way is to reload ones' self so as to be sure the load and the bullet and the primer is correct for the gun.