• Larger ammunition capacity: semi-automatics typically carry around 8 to 20 rounds; whilst most revolvers carry between 5 and 8 rounds. 
• Faster reloading: Magazines can be swapped more quickly than the cylinders of a revolver can be reloaded, and the operation is simpler. Magazines are also easier and more convenient to carry than the loose ammunition or speedloaders needed for revolvers. 
• Semi-automatics often have a significantly slimmer and easier to conceal frame as they do not suffer from the bulge produced by cylinder of a revolver. 
• Some modern semi-automatics have frames made of polymers, making them lighter and more comfortable to carry for long periods. This can also serve to absorb some of the recoil energy when a round is fired. Revolver frames are rarely made of polymers, though the Ruger LCR is an exception to this. Weight savings from a polymer framed revolver would be less than for a semi-automatic as the main sources of weight in a revolver are the barrel and cylinder which cannot be made from polymers. 
• On single action and double action semi-automatics the trigger pull can be lighter than on revolvers—constantly in the case of single actions, and after the first round in that of double actions. This can allow for greater accuracy and faster follow-up shots. Revolvers will always have strong trigger pulls unless the hammer is cocked before each shot, which significantly slows the shooter's rate of fire. Double action only semi-automatics do not have this advantage. 
• The risks of hangfires are reduced in semi-automatics in comparison to revolvers. When a hangfire occurs in a revolver, the cylinder could be rotated after the primer is struck but before the hung round fires, especially during rapid firing. This can result in a round firing from a chamber not aligned with the barrel and can damage the revolver and potentially injure the shooter. In a semi-automatic the hung round remains in the chamber, which is always aligned with the barrel, until it fires or the shooter deliberately ejects it by racking the slide. Once ejected, the hung round still poses a threat but the risk is greatly reduced. 
• Some semi-automatics incorporate an external safety switch, which prevents the gun from firing. Most revolvers do not have such a feature, though the same is true of many semi-automatics. There is debate over whether external safety switches are necessary, particularly in models with trigger-activated firing pin blocks, though many users prefer them for peace of mind regardless of whether or not they are safer. 
• Quieter: With similar ammunition, a semi-automatic is typically slightly quieter. Flash and noise can be suppressed. Noise and flash suppressors are ineffective in most revolvers due to noise and flash escaping the gap between the cylinder and the barrel. 
• Less expensive ammunition: semi-automatics often fire standard military ammunition, which is more readily available and cheaper thanks to extensive mass production. However, some revolver cartridges such as .38 Special are comparable in their cost and availability to popular autoloading cartridges such as 9mm Parabellum and .45 ACP.