M16 Vs AR15 : Know Actual Difference Between Them

If you have a surface knowledge about rifles and use of rifles, then you might not know about all the variants of rifles that exist. But still, you should be able to recognize an M-16 or AR-15 rifle when you see it. They are two of the most popular rifles out there.

When talking about M16 vs AR15, it not very uncommon for someone to mix them up as the same rifle. Both of them have a similar kind of style in appearance.

Also, they have evolved by using similar kind of technologies in their build over the years. Due to this, mainstream media quite often labels these two popular rifles as the same firearm. But upon closer inspection, you can find the distinct differences between the two rifles.

In this article, we will find out the real differences between the M16 and AR15 by talking about their history, features, advantages etc.

All You Need to Know About M-16

About M-16

The M16 is an assault rifle which was originally developed in the United States by Colt. It is a military grade weapon, often considered to be the US military version of the legendary Armalite AR-15 rifle.

It is used as a standard issue shoulder weapon which uses 5.56 mm caliber. Although it was not very popular at the beginning, with tough testing and training it became one of the most iconic assault rifles ever.

Here is a detailed analysis of the M16 rifle.


For the United States military, the need for making a rifle like the M16 rose after the events of World War II. They were on a mission to replace previous machineries used like M1 Garand, M1/M2 Carbines, M3 “Grease Gun” and Thompson submachine gun for a singular automatic rifle.

The previously used firearms were deemed to be failures in combat experience for being under-powered. So, the US Army started testing other weapons trying to find a replacement.


The M14 was the initial replacement but that too did not sustain for being too heavy and carrying less ammo. During that period, the AR-15 rifle was the most perfect weapon that fit the requirements of the US Army. The proposal to use AR-15 as the main rifle was rejected despite it bringing more firepower to the table for the military.

In 1956, Colt’s Manufacturing Company designed a scaled down version of the Armalite AR-15 rifle. Some key modifications were brought by the company which made this rifle a superior one over the currently used M14. The newly redesigned gun was adopted by the US military in the year 1964. The weapon was named Rifle, Caliber 5.56 mm, M16.

Build and Features

The M-16 rifle is a lightweight, gas operated, air cooled, magazine fed, shoulder weapon. The rifle is regarded as a top-level firearm for its lightweight, accuracy and volume of ammunition. It possesses three modes of shooting: safe, automatic, and semi-automatic.

Some variants of the rifle also had a three-round burst mode. It also features an adjustable rear sight. The receivers of an M16 are of aluminum alloy. While the other parts such as barrel, bolt and bolt carrier are made of steel. Plastic is used to make the grip, handguard, and buttstock of the rifle. Depending on the variant, the weight of an M16 rifle ranges between 3.6-4 kgs with a loaded magazine of 30-rounds. The length of a rifle is approximately 39.6 inches.

Different adjustments were brought to different variants of the rifles which improved its performance over the years. Some mentionable variants are:

  • M16A1
  • M16A2
  • M16A3
  • M16A4


During the preliminary years of development, the M16 rifle was known for poor reliability and chronic malfunctions. But years of development turned this rifle into one of the most iconic assault rifles.

The advantages of an M16 rifle are:

  • The rifle is comparatively very light in respect to other known rifles. Slimmer 5.56mm bullets are used which make the rifle lighter.
  • Because of being slim, the bullets travel really fast, allowing it to have a longer range. Its maximum effective range is 400-500 meters.
  • M16 rifle has less recoil making it a very smooth operating firearm. Due to lesser recoil, the rifle moves very little white shooting and is easier to control during automatic mode. That also increases accuracy.
  • The M16 is known for its ergonomic build. This enhances user experience by placing the firearm very comfortable in the users’ hands.

All You Need to Know About AR-15

About AR 15

The AR-15 rifle, originally known as Armalite AR-15, is described as a semi-automatic lightweight rifle. The AR-15 as we know it now was also developed by Colt in the United States.

It is the civilian version of the M16 rifle used by the United States military services. But unlike its counterpart, this only shoots in semi-automatic mode. In recent years, the AR-15 has become talk of the media because of mass shooting incidents in the United States.


The modern day semi-automatic AR-15 was originally called Armalite Rifle-15 because of their producers ArmaLite. But in 1959, ArmaLite faced serious financial crisis and decided to sell their patent and trademark to Colt’s manufacturing company. After retaining exclusive rights to the rifle, it was named the Colt AR-15 rifle. Since the year 1964,Colt started mass producing the AR-15.

AR 15 History

The initial version of the AR-15 produced by Colt was called Colt AR-15 Sporter. Over the years, Colt also produced improved and different variants of the rifle.

Some of the popular variants are:

  • AR-15
  • AR-15A2
  • AR-15A3
  • AR-15A4

Build and Features

The AR-15 rifle is an air cooled, magazine fed rifle which is operated by gas. The rifle has two shooting modes: safe and semi-automatic (single shot). Since it is a civilian rendition of the M-16, this does not come in full automatic mode.

The AR-15 is not an assault rifle. It is categorized as “Modern Sporting Rifle”. It possesses a straight line recoil with a rotating bolt design. Aluminum and synthetic materials were mostly used to produce this rifle. State of the art machinery like Computer Numerical Control (CNC) is used to manufacture this firearm.

The AR-15 is regarded as a Modular Weapon System. It means that you can easily assemble, repair, and modify parts of the rifle by using common hand tools.

AR-15 rifles possess two receivers- the upper receiver and the lower receiver. If you look closely, you can locate the fore stock, the charging handle, the barrel, the gas operating system, the bolt assembly in the upper receivers. The lower receivers allocate the grip, the magazine well and the buttstock. It also allocates the trigger, hammer, and fire selector.

The AR-15 rifle features an exclusive ergonomic structure containing the carrying handle and rear sight on top of upper receivers. The weight of an AR-15 rifle is approximately 3 kg with a 20-round magazine. It used .223 cartridge bullets inside the magazine. The rifle is 39 inches in length.


The AR-15, being a civilian version of the M-16 rifle, is greatly advantageous to the common mass. For home safety purposes, this rifle is very popular.

The advantages of AR-15 rifle are:

  • AR-15 rifle features multiple points of contact providing greater stability to the firearm. It is also very easy to aim and the accuracy of firing also helps you to shoot any intruder from some distance.
  • It is very easy to store this weapon safely in a household. You can use a two-point sling to keep the rifle at any place in the house.
  • You can easily manage this rifle for being lightweight. Almost any member of the house can use this rifle carefully and efficiently.
  • The AR-15 rifle has almost no recoil while shooting. So even if you are not a professional, you can shoot accurately with this rifle.
  • Having regarded as an apt firearm for home defense purposes, you can have a good level of flexibility in case of choosing ammunition for this rifle. This helps to lower down casualty rates.

M-16 vs AR-15: What Makes Them Different?

What Makes Them Different

If you have read this far then you must be wondering what makes two of these iconic rifles so different from each other. Because if you do not realize, a lot of similarities also exist between the two.

After all, both of these rifles are manufactured by the same manufacturing company. In spite of the similarities, a lot of key features show how these rifles are different from each other and are meant for two different things.

The differences between rifles M-16 and AR-15 can be seen in the following categories:


Both the M-16 and AR-15 are rifles, but they came into being to serve different purposes. The M-16 as we know now, was created at the height of the Cold War to give the US military a deadly, accurate and lightweight rifle to compete against the Soviets.

It was also used for jungle warfare operations during Vietnam war. On the contrary, the AR-15 is a modern day rendition of the original ArmaLite Rifle-15. It was designed with maximum customizability in mind to produce the most accurate and effective civilian sharpshooting rifle.

So, you can see how these two rifles are meant to serve different purposes.

Rifle Category

Although both the M-16 and AR-15 might look similar in build and appearance, they are not of the same rifle category.

The M-16 is a military grade weapon used by military services all over the world. It is described as a fully automatic assault rifle. It is also sometimes called a machine gun because of having full automatic shooting capabilities.

On the other hand, the AR-15 is not an assault rifle. It is categorized as a modern sporting rifle. It possesses semi-automatic shooting which means you can only shoot once per trigger.

So, both these rifles are of different categories.


Fundamentally, both the AR-15 and M-16 are built in the same way. They also sort of function the same with some minor modifications to each of them. Both the rifles possess a lower and upper receiver which stores the rifle components.

Also, both the rifles feature a barrel, front and rear sights, a magazine well, a charging handle, a bolt assembly, a buttstock, a trigger, and a compensator.

So, you can see how similar in build these rifles are. The real difference lies in a hole on the side of the M-16, just above the handgrip of the rifle. This hole is called the auto sear, which makes the M-16 a machine gun.Due to the presence of this, M-16 can shoot in full automatic mode.

This hole is absent in the AR-15.


When it comes to availability, getting an AR-15 is way easier to get than an M-16. And it is because of obvious reason. The M-16 rifle is a military grade weapon used only in military services.

So, a civilian is never supposed to acquire an M-16 for home security purposes. It is illegal for a person to possess an M-16 rifle without having authorized clearance from the National Firearms act.

The process of getting this authorization is also very complex and expensive. On the other hand, the AR-15 was customized in a manner to make it available for an average civilian to use.

So, for an average person, getting an AR-15 rifle is easier.

Shooting Mode

In case of shooting modes, both these rifles have a slight difference. The safe mode and semi-automatic mode, both are present in each of the rifles.

Shooting Mode

But only the M-16 has a built in fully automatic shooting mode, making it a military class weapon. Depending on the variant, some of them also possess burst shooting mode as well.

Weight and Range

Known from the raw data, both the M-16 and AR-15 both weigh in about 7 pounds or 3.2 kgs when fully loaded.

The M-16, being a military grade weapon, has an average effective shooting range of 550 meters. On the contrary, the AR-15 has a lower shooting range of 400-600 meters.

Magazine and Cartridge

Both the rifles, M-16 and AR-15, feature a standard size 30-round magazine in their magazine well. But some variants of AR-15 also feature a 20-round magazine.

The M-16 fires the mor improved 5.56mmx45 mm NATO cartridges. While the AR-15 rifle fires the 5.56mmx45 mm NATO cartridge or the .223 Remington cartridge.


If you want to compare the usability of both the M-16 and the AR-15, then the AR-15 is the right way to go if you are an average user. The lightweight of the AR-15 rifle makes it easier for someone to hold and use for a prolonged time without catching fatigue.

The recoil of the AR-15 is also very low. As a result, it is easier to maintain accuracy and shoot effectively with it. It is also very easy to store inside a household.

But the M-16 is rather difficult to use when compared to the AR-15. Because of being a military assault rifle, it is a bit more on the heavier side and the recoil is also comparatively more. This makes it a challenge for a normal user to use it in times of danger.


If security is a concern for you, then you should pick the AR-15 over the M-16. The M-16 is not a firearm made for safety reasons. It is a military grade combat gun used in wars.

On the other hand, the AR-15 is safer comparatively because of its single shot firing mode. With an automatic machine rifle like the M-16, the consequences of an accident can be much dire.

Also, since the AR-15 was designed as a civilian counterpart to the M-16, it is appropriate to use this for safety reasons.


In case of customization, the AR-15 does have the advantage over the M-16. AR-15 has more scopes for mixing and matching in case of uppers and lowers. This allows the AR-15 users to modify the caliber of their rifle from the standard .223m up to a .50 caliber BMG.

Also, AR-15 users can change their standard 30-round magazine to a wide range of magazines, including a 100-round drum magazine. But the scope of customization is limited in a M-16 rifle since it is mostly used in the war field.


When it comes to the topic of M16 vs AR15, the similarities and dissimilarities between the two rifles are hard to identify.

Due to misleading news from the mainstream media, you might often end up thinking that the two mentioned rifles are somewhat the same rifle.

Although similar features between the two are more in number, there are subtle differences between the two rifles which create two different weapons for two different occasions.

The article covers the features of the two rifles in depth. And it also points out the advantages and disadvantages of owning these rifles. So going through this article will help you get a clearer idea about these two iconic rifles and will help you make a better decision in case you are trying to acquire one.

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