Introduced very early in the cartridge era (I have never found a trustworthy date claimed in any of my not insubstantial research), the 38 Short Colt was originally called the 38 Colt. It was designed to work in converted 1851 Colt Navy revolvers using one of at least three common conversions. The 38 in the name reflects outside diameter of the case mouth. With the 1875 introduction of the 38 Long Colt, this round was given the retronym, 38 Short Colt. The necessary insert that replaced the rear of the original cylinder with firing pins for each chamber limited the amount of length remaining for the cartridge to occupy. This significantly limited bullet length, propellant charge, and therefore performance. The biggest issue with the conversion systems was the necessity of using a heal-based bullet and external bullet lubrication in the 38 Colt cartridge designed to work in the converted cap-and-ball revolvers. Both factors hindered accuracy. The latter issue was very problematic because the limited amount of lube was generally inadequate and what little there was tended to get wiped off and contaminated. Modern 22 Rimfires use the same system but, because those are loaded with smokeless powder, do not require as much lubrication. And the 22 rimfires can use hard-wax lubricant that would not work with blackpowder. An attempted solution was to modify the design to use a conventional, hollow-based bullet with the lubrication moved below the case mouth. These rounds depended on bullet obturation to fill the cylinder and then the bore. If made from very soft (necessarily very pure) lead, sometimes, this system worked. Common impurities in the lead of less than 1 part in 100 could render the lead hard enough to prevent obturation. So, because getting pure lead was difficult in that era, all too often, obturation was absent or inadequate and accuracy was dismal, at best. As with any revolver round, best practice is to apply a roll-crimp after seating the bullet. This helps to lock the bullet in place against chambering forces that might otherwise drive it into the case. I cannot too-strongly recommend getting a second seating-and-crimping die so you can have one adjusted to only seat the bullet and the second adjusted to only crimp the case mouth. Generally, attempting to do both operations in one step is a recipe for damaged and destroyed cases.