Handloading or reloading is the process of loading firearm cartridges or shotgun shells by assembling the individual components (case/hull, primer, powder, and bullet/shot), rather than purchasing completely assembled, factory-loaded ammunition. Boxer-primed cases are more commonly reloaded. (See centerfire ammunition.)
Historically, handloading referred to the private manufacture of cartridges and shells using all newly manufactured components, whereas reloading referred to the private manufacture of cartridges and shells using previously fired cartridge cases and shotgun hulls using new bullets, shot, primers, and powder. In modern usage, some make no distinction between these terms, while others find important distinctions. One distinction is the purpose for the practice; handloaders often seek smaller batches of high-quality ammunition, whereas reloaders are said to make large quantities of ammunition that does not need to be of as high quality. At least one authority (McPherson) holds that a better distinction for these connotations is that, regardless of quantity, handloads tend to be of generally high quality while reloads tend to be merely functional.
Economy, increased accuracy, performance, commercial ammunition shortages, and hobby interests are all common motivations for handloading both cartridges and shotshells. Reloading fired cartridge cases can save the shooter money, or provides the shooter with more, and higher quality, ammunition within a given budget. Reloading may not be cost effective for occasional shooters, as it takes time to recoup the cost of the required equipment, but those who shoot on a regular basis will see benefit as the brass cartridge case or shotgun shell hull (the most expensive components) can be reused many times (with proper maintenance). Besides economy, the ability to customize the performance of ammunition is a common goal. Hunters may desire cartridges with specialized bullets or specific performance as regards bullet and velocity. Target shooters seek the best achievable accuracy, as well as the best shot-to-shot consistency, or precision. Shotgunning enthusiasts can make specialty rounds not available in commercial inventories at any price. Many handloaders also customize their cartridges and shells to their specific firearms, usually in pursuit of accuracy: they can assemble precision ammunition using cartridge cases that have been fire formed in the chamber of a specific firearm.