Because that’s all I have seen them used for

Your unfamiliarity with a subject doesn’t dictate its definition.

The AR-15 and machine guns are fundamentally different types of firearms in terms of design, function, and legal classification. Here’s a breakdown of the key differences:

1. Firing Mechanism:

• AR-15: The AR-15 is a semi-automatic rifle, meaning it fires one round per trigger pull. After each shot, the rifle automatically loads the next round into the chamber, but the trigger must be released and pulled again for another shot to be fired.

• Machine Gun: A machine gun is fully automatic, meaning it can fire continuously as long as the trigger is held down. It will keep firing until the trigger is released or the ammunition is depleted. Machine guns are capable of sustained rapid fire, often at rates of several hundred rounds per minute.

2. Legal Status:

• AR-15: In the U.S., the AR-15 is classified as a civilian firearm and is legal to own in most states, subject to local laws and regulations. Because it is semi-automatic, it does not fall under the same strict regulations as fully automatic firearms.

• Machine Gun: Fully automatic machine guns are heavily regulated in the U.S. under the National Firearms Act (NFA) of 1934 and the Firearm Owners’ Protection Act (FOPA) of 1986. Under current law, civilians can only legally own machine guns made before 1986, and the process requires extensive background checks, registration, and tax payments.

3. Intended Use:

• AR-15: The AR-15 is often used by civilians for purposes such as sport shooting, hunting, and home defense. Its modular design allows for customization with different accessories like scopes, stocks, and grips.

• Machine Gun: Machine guns are primarily intended for military or law enforcement use due to their ability to provide suppressive fire and high rates of fire. They are rarely, if ever, used by civilians in legal activities due to their full-auto nature and high ammunition consumption.

4. Physical Design:

• AR-15: The AR-15 looks similar to military rifles like the M16 and M4, but it lacks the full-auto or burst-fire capabilities. It typically fires smaller cartridges like the .223 Remington or 5.56x45mm NATO.

• Machine Gun: Machine guns can vary in size, from light machine guns (LMGs) that are carried by infantry, to heavy machine guns mounted on vehicles or tripods. They are designed to fire continuously with belts of ammunition or large magazines, often with barrel cooling systems to prevent overheating.

Summary:

• AR-15: A semi-automatic civilian rifle that fires one shot per trigger pull.

• Machine Gun: A fully automatic firearm that fires continuously while the trigger is held down and is heavily regulated for civilian ownership.

In conclusion, the AR-15 is a semi-automatic rifle popular among civilians, whereas a machine gun is a fully automatic firearm, typically used in military contexts, with significant legal restrictions for civilian use.