Semi-automatic firearm

This tool can fire many times.

It uses energy to load itself. The power from one shot helps it work. It moves a part to load new food.

You must pull the trigger for every shot. You must let go of the trigger first. This lets it get ready again.

It can be a gun for a person or a soldier. It can be a small pistol or a long rifle.

A semi-automatic firearm is a tool that can fire many shots. It uses a special way to load itself. When a shot is fired, it lets out power. This power comes from recoil or gas. This power moves a part called the bolt. The bolt moves to take out the old case. It also puts a new round into the chamber. This happens without the user doing anything.

Even though it loads itself, it is not fully automatic. A user must pull the trigger for every single shot. You must let go of the trigger to reset it. Then you can pull it again to fire.

Many people helped make these tools. Ferdinand Ritter von Mannlicher made a successful design in 1885. John Browning made a successful shotgun in 1902. Later, the M1 Garand became a famous rifle. It was used by the U.S. Army in World War II.

Today, some rifles can switch modes. They can be semi-automatic or fully automatic. Most rifles for civilians are semi-automatic only.

A semi-automatic firearm is a repeating tool that loads itself. It is also called a self-loading or autoloading firearm. This device is special because it handles the hard job of loading the next shot. You do not have to move parts by hand between every shot. However, it is not the same as a fully automatic weapon. In a fully automatic weapon, the tool keeps firing as long as you hold the trigger. In a semi-automatic weapon, you must pull the trigger for every single shot. You have to release the trigger to let it reset before you can fire again.

How does this tool work so quickly? It uses the energy left over from the shot that just happened. This energy comes from recoil or from high-pressure gas inside the bore. This energy moves a part called the bolt. The bolt moves to unlock and pull the empty case out of the chamber. At the same time, the bolt moves a new cartridge into the chamber. This happens all by itself without any help from the user. This way of working is often called a closed-bolt system. In this system, the round is already in the chamber before you pull the trigger.

Many clever people helped invent these designs over a long time. An Austria-born gunsmith named Ferdinand Ritter von Mannlicher made the first successful design in 1885. He made the Model 85 and later the Model 91, 93, and 95 rifles. Another famous inventor was John Moses Browning. In 1902, he made the Browning Auto-5 shotgun. This was the first successful semi-automatic shotgun. It used a design called long recoil operation. This specific way of working stayed popular for about 50 years. The production of that shotgun finally ended in 1998.

Different nations used these tools in famous wars. The United States Army adopted the M1911 handgun in 1911. Later, the M1 Garand became a very important rifle. It was developed by John Garand at the Springfield Armory in Massachusetts. The first production model of the M1 Garand came out in 1937. It was a gas-operated rifle that helped American soldiers in World War II. Other countries also made rifles like the Soviet SVT-38 or the German Gewehr 43. In 1945, Sergei Gavrilovich Simonov designed the SKS rifle. The SKS was the first widely used weapon to use the 7.62x39mm cartridge.

Today, we see many different types of these tools. Some are made for soldiers and can switch between modes. These are called selective-fire firearms. They can act as semi-automatic or as fully automatic. Most rifles made for civilians, like the AR-15, are semi-automatic only. Some people use the word "automatic" to mean a self-loading tool. To avoid confusion, experts often call them "autoloaders" instead. This helps people know if they are talking about the loading way or the firing way. Knowing these details helps us understand how modern tools work.

A semi-automatic firearm is a repeating weapon that handles its own loading process. It is also known as a self-loading or autoloading firearm. While these weapons can fire many shots in a row, they differ from fully automatic weapons in one major way. In a fully automatic weapon, the firearm continues to discharge rounds as long as the trigger is held down. In a semi-automatic firearm, the shooter must manually actuate the trigger for every single shot. This means each trigger pull discharges only one round. To fire again, the user must release the trigger to allow it to "reset" before pulling it once more.

The mechanism relies on the excess energy released during a shot to prepare the next one. This energy typically comes in two forms: recoil or high-pressure gas expanding within the bore. When a shot is fired, this energy is used to unlock and move the bolt. The moving bolt performs several tasks in a specific sequence. First, it extracts and ejects the spent cartridge case from the chamber. Next, it re-cocks the firing mechanism and loads a fresh cartridge into the chamber. This entire cycle happens automatically without any manual input from the shooter.

Most semi-automatic firearms use a closed-bolt firing system. In this system, a cartridge is already chambered before the shooter pulls the trigger. When the trigger is pulled, only the hammer and firing pin move to strike the cartridge. This method is generally more accurate because the center of gravity changes very little during the shot. In contrast, an open-bolt mechanism is common in fully automatic weapons. In an open-bolt system, pulling the trigger releases a cocked bolt from a rearward position. This movement pushes a cartridge into the chamber and fires it instantly. While open-bolt systems allow air to circulate and cool the barrel, closed-bolt systems are preferred for the accuracy required in semi-automatic use.

History shows a long progression of these mechanical designs. The first successful design for a semi-automatic rifle was created by Ferdinand Ritter von Mannlicher in 1885. He produced the Model 85 and later the Models 91, 93, and 95. In 1902, American gunsmith John Moses Browning developed the Browning Auto-5. This was the first successful semi-automatic shotgun and used a long recoil operation. This specific design remained the dominant method for shotguns for approximately 50 years until production ended in 1998.

Different types of actions were developed to manage these processes. For example, the Winchester Model 1903 and 1905 used a blowback principle. These were the first semi-automatic rifles designed specifically for the civilian market. Other weapons used gas-operated actions, which use the gas from the fired shot to move the mechanism. The French Fusil Automatique Modele 1917 was the first semi-automatic gun to be widely issued to infantry. Although it did not receive a favorable reception, its improved version, the Model 1918, was better received during the Moroccan Rif War from 1920 to 1926.

Military adoption of these weapons changed the nature of combat. In 1937, the American M1 Garand became the first semi-automatic rifle to replace a nation's standard bolt-action infantry weapon. Developed by John Garand at the Springfield Armory, this gas-operated rifle gave American infantrymen an advantage during World War II. Other nations also introduced semi-automatic rifles during the war, such as the Soviet SVT-38 and the German Gewehr 43. However, these did not fully replace the standard bolt-action rifles in those armies. In 1945, Sergei Gavrilovich Simonov designed the SKS, which was the first widely issued weapon to use the 7.62x39mm cartridge.

Today, firearms are categorized by their firing capabilities. Some modern service rifles, like the M4 carbine, are selective-fire. This means they can switch between semi-automatic and automatic or burst-fire modes. Most civilian versions, such as the AR-15, are restricted to semi-automatic operation only.

Because the term "automatic" can be confusing, experts often use different labels. In the context of handguns, "automatic" usually distinguishes a semi-automatic pistol from a revolver. To avoid any misunderstanding regarding the loading mechanism, many people prefer the term "autoloader." Understanding these distinctions helps clarify whether a person is discussing how a gun loads or how it fires.