.38 rimfire cartridges are a type of ammunition that have been in service in the United States since the mid-nineteenth century. The cartridges are produced in short, long and extra long variants. Much like the smaller .32 rimfire, the rounds were originally manufactured loaded with black powder. In the early 1900s, manufacturers switched to the "new" smokeless powder. The .38 rimfire was preferred to the .32 rimfire for hunting and self-defense purposes because of its larger size and increased power.