Some reloading and gun handling points need to be emphasized. Some of you mentioned the reloading aspect, but didn't see anyone mention "fanning."
1. Black powder requires a soft lead bullet, very nearly pure lead.
2. Bullets must be lubricated with a moist lubricant made for black powder, such as SPG, Lyman Black Gold or the home-brew lubricant named after me: Gatofeo No. 1 Bullet Lubricant (search the net).
One poster said he was going to use beeswax and Crisco, and he's on the beam with that combination.
3. Black powder burns best when slightly compressed.
4. Magnum primers are unnecessary in the small volume of the .38 Special case. I use Winchester primers for all my black powder loads, as they tend to run a little hotter than CCI. But I've also used CCI without a problem.
5. Crimp the bullet well, but it's soft so be careful not to damage it. A firm crimp aids ignition.
The .38 Special cartridge was originally a black powder round, when introduced about 1899. After a few years, smokeless powder was introduced in it, but factories continued to make black powder .38 Special cartridges up to about World War I.
Now, as to "fanning"
Fanning is holding the trigger back with your finger and slamming the hammer back your other hand, to shoot rapidly. It's inaccurate and will damage the gun.
Fanning is terribly hard on gun parts, causing them to slam and grate against each other when not fully engaged. Typically, the spur on the top of the trigger gets broken, or the notches in the hammer are damaged.
Never fan a revolver unless it's specifically made to do so. This means grinding off the top spur of the trigger that engages the notches in the hammer. With this trigger spur gone, it cannot contact the hammer.
But slamming the hammer back also slams the pawl -- that doohickey that comes up through the frame to turn the cylinder and the bolt, which comes up through the bottom of the frame to lock up with the cutouts in the cylinder.
Fanning is just bad business all around.
A revolver can be made for fanning, but it requires a gunsmith who knows what he's doing.
Look up Ed McGivern on the internet, who was one of the fastest shooters with a revolver in the world some 70 years ago. He did some fanning work and got groups at 15 feet the width of his hand. But he was an exception. Fanning is largely inaccurate unless you shoot a fluke grouping.
Shooting black powder pistol cartridges is definitely fun. I enjoy those I load.