Difference Between AR15 And M16 Rifles

The AR-15

The AR-15, short for “ArmaLite Rifle-15,” has its roots in the late 1950s when American engineer Eugene Stoner designed it for the Armalite Corporation. Initially developed as a lightweight military rifle, Armalite soon sold the patent to Colt’s Manufacturing Company in 1959, which began mass-producing it. The AR-15 later became the basis for the military’s M16 rifle, which was the main rifle during the Vietnam War.

Design and Features

  • The AR-15 is a gas-operated, air-cooled, semi-automatic rifle. It operates on the direct impingement or gas piston principle.
  • It typically chambers the .223 Remington or 5.56x45mm NATO cartridge, but many variants can accommodate other calibers.
  • The AR-15 is known for its modular design, featuring a lower receiver (the “firearm” component) and an upper receiver that can be easily swapped out for different calibers, barrel lengths, and handguards.
  • It has a detachable magazine, often with capacities ranging from 10 to 30 rounds or more.
  • A variety of furniture options, such as adjustable stocks, pistol grips, and handguards, allow for customization to suit individual preferences.

The AR-15 is popular among civilian gun owners, particularly in the United States. Its adaptability and customization options have created a robust market for accessories and modifications, allowing users to tailor the rifle to their specific needs. It is used for various purposes, including hunting, target shooting, and home defense.

Many manufacturers produce AR-15-style rifles and components. Some common variants include the Colt AR-15, Bushmaster XM-15, Smith & Wesson M&P15 and many others. Some versions have shorter barrels and collapsible stocks.

The AR-15 has been a focal point in debates about gun control in the United States. Advocates for stricter gun control argue that the AR-15 is often used in high-profile mass shootings due to its accessibility and firepower. Supporters of the Second Amendment argue that the AR-15 is a versatile firearm suitable for legitimate purposes, and banning it infringes on their rights.

The M16

The M16 is derived from the AR-15 rifle. In 1963, the U.S. military adopted the AR-15 as the M16 rifle and began using it during the Vietnam War. The M16 was designed to be a lightweight, selective-fire rifle, capable of semi-automatic and fully automatic firing modes.

The M16 faced controversies during the Vietnam War when early models experienced issues with reliability and jamming in adverse conditions. These issues were largely attributed to the use of a different type of gunpowder in the ammunition than originally designed, but they were later addressed with improvements in subsequent M16 variants.

After the Vietnam war, several iterations and improvements were made over the years, including, the adoption of the three-round burst mode aimed to reduce ammunition wastage in automatic fire. This culminated to the M16A4, which became the standard service rifle for the U.S. Marine Corps.

Design and Features

  • The M16 is chambered for the 5.56x45mm NATO cartridge, designed to be lightweight and have low recoil.
  • It operates on the gas-operated, rotating bolt principle, which uses expanding gas from the fired cartridge to cycle the action.
  • The M16 features a detachable magazine, typically holding 20 or 30 rounds.
  • It has a range of attachments and configurations, including bayonets, grenade launchers, and various optics.
  • The original M16 had a full-auto firing mode, but it was later replaced with a three-round burst mode for improved control and ammunition conservation.

Over the decades, the M16 platform has given rise to numerous variants, including the M16A1, M16A2, M16A3, and M16A4, each with specific features and improvements. The M16 also led to the development of the M4 carbine, a shorter and more compact version favored by U.S. military personnel, particularly those in close-quarters combat roles. Other countries have adopted their versions of the M16, such as the Canadian C7 and the Singaporean SAR 21.

The M16 and its variants have seen service in numerous conflicts, including the Gulf War, Iraq War, Afghanistan War and Ukraine war. Its lightweight design, modularity and accuracy have contributed to its long-lasting appeal in military circles.

In recent years, the U.S. military has been transitioning from the M16 to the M4 carbine as the standard infantry rifle. The M4 retains many design elements of the M16 but offers greater maneuverability in tight spaces and is favored by special operations units.

AR15 vs M16: Key Differences

Firearm Classification

  • The AR-15 is typically available to civilians and is considered a semi-automatic rifle, which means it fires one round per trigger pull. The M16 is a military rifle, capable of firing in both semi-automatic and fully automatic modes, allowing for continuous fire as long as the trigger is held down.

Select-Fire Capability

  • AR-15 rifles are generally not designed with a select-fire capability, meaning they cannot fire in fully automatic or burst modes. The M16 can be configured for both semi-automatic and fully automatic fire, depending on the specific model and military requirements.

Civilian Ownership

  • In many countries, including the United States, civilians can legally own and purchase AR-15 rifles with semi-automatic capabilities. Fully automatic firearms like the M16 are typically restricted or heavily regulated for civilian ownership in many countries, including the United States.

Barrel Length

  • The barrel length of an AR-15 can vary, but it is often shorter compared to the M16, which makes it more maneuverable. M16 rifles typically have longer barrels for improved accuracy and muzzle velocity.

Bayonet Lug

  • Many AR-15 rifles do not include a bayonet lug, as they are designed primarily for civilian use. M16 rifles often include a bayonet lug as they are military rifles, allowing for the attachment of a bayonet.

Flash Suppressor

  • Some AR-15 models have flash suppressors, which help reduce muzzle flash and improve shooter visibility. M16 rifles often come with flash suppressors for military use to reduce the shooter’s visibility in low-light conditions.

Grenade Launcher Attachment

  • AR-15 rifles are not typically designed to accommodate grenade launcher attachments. Some versions of the M16 can be equipped with under-barrel grenade launchers.

Markings and Features

  • AR-15 rifles often lack military markings and features specific to the M16, such as a forward-assist and a dust cover. M16 rifles typically have military-specific markings, a forward-assist for chambering rounds, and a dust cover to protect the internals from debris.

Ammunition Compatibility

  • AR-15 rifles are commonly chambered for civilian cartridges, such as .223 Remington or 5.56x45mm NATO. M16 rifles are chambered for the 5.56x45mm NATO cartridge, which is a standard military round.

Legal Regulations

  • In many jurisdictions, AR-15 rifles are subject to varying regulations, but they are generally more accessible to civilians than fully automatic firearms like the M16. The M16 is heavily regulated for civilian ownership due to its fully automatic capabilities and is often restricted to military and law enforcement use in most countries.

Key Takeaways: AR-15 vs M16

Firearm TypeSemi-automatic civilian rifleSelective-fire military rifle
Legal OwnershipGenerally available for civiliansRestricted to military and law enforcement
Firing ModeSemi-automatic (one shot per trigger pull)Selective-fire (semi-auto and full-auto)
Barrel LengthVarious barrel lengths, often 16 inchesTypically 14.5 or 20 inches
Civilian VersionsAvailable in various configurations and brandsRestricted to civilian models
Bayonet LugOften lacks a bayonet lugTypically has a bayonet lug
Flash HiderMay or may not include a flash hiderTypically includes a flash hider
HandguardVarious handguard styles availableMay have a heat shield or unique handguard
MagazineUses detachable magazinesUses detachable magazines (usually 20 or 30 rounds)
MarkingsTypically lacks military markingsTypically marked as “M16”
Full-Auto CapabilityGenerally not capable of full-auto fireCapable of full-auto fire when set to that mode