Try the Goex powder website, they have an extensive database for loads and velocities on cap and ball BP loads, as well as other black powder loads, rifle, shotgun and cartridge. I placed a link in the related links section to the page.
It would depend on how the cartridge was loaded, ( powder type and amount and bullet weight's) A modern black powder load would be to about 100 yards. After that the velocity and energy drops dramatically. Smokeless powder loads would extend a bit farther.
Black powder and smokeless powder are two totally different animals. For all intents smokeless is meant for loading cartridges and black powder is used for muzzle loading fire arms. Black powder can also be used in cartridge loads. You have heard terms referring to a gun in 45-70 on 38-20 or 44-40 calibers. Those numbers refer to the caliber (45) and the amount of black powder in the cartridge (70 grains) Smokeless powder should NEVER be used in place of black powder in muzzle loaders, or in the same volume as black powder in cartridge loads. So depending on what you are shooting both powders have there place.
45 long colt ammo for modern weapons. If black powder weapon should only used re-loads with black powder
The powder charge for a .44 caliber revolver can vary depending on the specific cartridge and load being used. For example, a typical load for .44 Special might use around 5 to 6 grains of Unique powder, while .44 Magnum loads can range from 20 to 28 grains of powder, depending on the bullet weight and desired performance. Always refer to a reputable reloading manual for precise measurements and safety guidelines.
Loads that carry more shot and powder.
You need to contact the maker or get a book on Blackpowder shooting that has loads in it. Different types of weapons and projectiles and powders will determine what is a safe load.
45/70 caliber center fire. But NOT factory loads. For the trapdoor the case must be loaded with black powder
For the most part I have used 15 to 18 grains of 3F powder for target plinking, with good constant results. I have used as much as 25 grains when using as a back up for hunting. Best to check with the manufacturer to see the "best load and maximum loads" they recommend.
Depending on the gr/ the harder you squeeze the more speed the bullet travels(lol)/
Most old Damascus barrels cannot hold the pressures of modern smokeless loads. I doubt that you will find any black powder loads for that type of barrel. Hang it on the wall and admire it.
Yes, the faster twists 1.50 and lower are designed to shoot saboted and / or patched round ball loads.
A ".38 +P revolver" is simply a .38 Special revolver which is rated to fire +P loads. It's still a .38 Special, and the +P doesn't change the dimensions of the round itself.