Few weapons have been so exposed in the media with the strength that we saw with the name AR-15. Much is made about this weapon of “high caliber” (the biggest blunder THAT SAID) About it cuts through any armor, that it destroys everything it hits … and other stupidities. In fact all this folklore is the result of an imposed culture in this country that a man armed with a pistol or a 38 caliber 380, a person is considered well armed. In the world there are countries that are truly democratic and where the public can buy the best tool to defend themselves and not imposed limitations naive and meaningless, such as limiting the sizes of 38 or 380. In the United States, for example, size 380, which in Brazil is the sense of gun shops, is considered the smallest size you can use someone with some efficiency due to its fraquíssimo stopping power. Some also cite the adjective “anemic” when talking about this ammunition.
Returning to the subject of this matter, we focused on the classic AR-15 rifle, which is one of the firearms most widespread in history and is in use in almost all Western countries in the form of weapon to use police or military, fighters in small rodents, or pests of the field, also known as weapon “Varmint” due to the fact of 5.56 mm ammunition to a size small but very high power, little damage to the fragile structure of the body of small animals . There was also a concept that, in the battlefield, if you kill the enemy soldier, he would be left behind. It would be one less. But if you hurt your enemy, you wear 3 soldiers, because they would have to carry their wounded, and still use an infrastructure to deal with these injuries, causing a powerful moral wear the enemy. On top of this concept, it was decided by the decrease in size to 5.56 mm. But do not think that this cartridge is not lethal. He is for sure, but considerably less potent than the 7.62 mm, used in the M-14 and U.S., which is still used by the Brazilian forces known as the FAL.

Above, the first AR-15 without any of the improvements that occurred after the failures in combat, and below, the model M-16 A1, with the close button of the bolt, even be used in cases of failure due to waste and debris excessive.

The AR-15 was designed by the genius designer Eugene Stoner who worked for the company Armalite-based, and not so well known AR-10, also created by Eugene, but in 7.62 mm caliber. In 1957 the U.S. army ordered a new rifle that uses a smaller caliber, the 308 Winchester, also known as 7.62 mm, which was light to travel with more ammunition for the soldiers. The ammunition had to be something in .22 caliber and capable of drilling a steel helmet standard to 500 meters. Eugene Stoner is used as the base of its AR-10 rifle and build the AR-15 caliber remington 223 or 5.56 X 45 mm, which was derived from a gauge remington 222 caliber, used to hunt small animals. In 1958 delivered the first Armalite rifles to the army for field testing, which ended up showing problems regarding the accuracy and reliability of the weapon. In 1959, the Armalite was disappointed with the unfavorable results of the AR-15 and sold the whole project and the company rights Colt, a very devoted arms manufacturer worldwide and Mr Eugene Stoner got into the factory of the Colt. And this year showed the Colt AR-15 to the commander of U.S. Air Force which purchased approximately 8000 rifles to replace the old M-1 carbines and M-2. In 1962, DARPA (Department of Advanced Projects of USA), 1000 purchased AR-15s and sent them to field tests in South Vietnam, and this fact has resulted in an order of 85,000 rifles to the army and 19,000 more for strength air. But the results in the field, and began to show concern for the AR-15 was with considerable operational problems that were being caused by the type of gunpowder that was used in the cartridges. This powder, IMR tubular Du Pont was used in 7.62 mm cartridges, caused a large and fast storage of carbon in the inner parts of the gun, and after hot, this deposit, cooled and hardened strongly like a glue Quick drying locking the weapon permanently. To avoid this type of occurrence would be necessary to clean the gun at all times, which was not a widespread practice in the mire that has become the Vietnamese battlefields. The replacement of gunpowder used, coupled with changes in the weapon as a new damping mechanism to reduce the rate of fire, the plating chamber and the gun barrels to avoid oxidation due to the humid environment of Southeast Asia has resulted in the M-16 A1 , a weapon that although he was confident, was struggling to erase a bad first impression that had been initially.

Above we can see an M-16 A2, which was the position of short bursts embedded in the key selection of shot, as a major mechanical changes for the AR-15 original.
In the late 70′s, the U.S. military and even the Colt began studying improvements that would be possible to apply the AR-15, and then, was the M-16 A2, a gun barrel heavier and durable, exchange pitch of rifling the barrel of 1:305 to 1:17, making it more appropriate to the type of ammunition used as standard SS109 NATO. The exchange of the tile with a new synthetic material more durable and still had available a new position on the dial of fire: the short raja of 3 shots.

Above and Below is the current model M-16, as A-4. This weapon sese become very effective with the adoption of divresos rails around the top and the tile, allowing quick mounting of accessories. Quality usually found in weapons of latest project.

Currently, this weapon is manufactured by many companies who have acquired the right to production and through further improvements had new versions, such as M-16 A3 working fully automatic or semi auto, using the same qualities and strength version A2 and still had a carrying handle replaced by a removable, the new version of M-16 A4, which again had the availability of the position of short bursts of 3 shots, and even had mounted a picatinny type rail, which allows the use of optical sights, which can be installed without a gunsmith. These picatinny rails, are also present in the tile to allow the coupling of flashlights, laser sights, cameras and grenades.

Above: Here is a copy of the M-16 A1 with M203 grenade launchers. This model was what has become standard for the M-16 equipped with one.

Above, we see an M-16 A4 with the M203 grenade launcher. Note the change in the design of the tile to allow the mounting of accessories, as well as grenade launchers.
Speaking of grenades, it is interesting to note that the M-16 A1, equipped with a grenade launcher, M-203 and 40 mm became very popular after the presentation of the movie “Predator,” where the actor Arnold Schwarzenegger, use one of these weapons. The grenades M-203, to a large potential for improvement in infant mortality with a device lighter than a rocket launch, or bazooca as some prefer, integrated into your main weapon, with flexible use. Many current army had adopted the grenades their rifles, after this modification was shown to be effective by using a pioneer in the United States Army.

Above, the Colt Commando rifle, which was the first model AR-15 short and put into service. Look at the great fire break at the tip of the barrel.
Subsequent to commissioning of the M-16, the United States Army, requested that we developed a smaller version of the M-16, for use in its special operations forces, like the Green Berets, and the short version was called the XM -177, and designated as the U.S. ARMY CAR-15 or “Commando”. This version had a barrel of 10 inches and a large fire break at the end because that weapon had huge flames when shot. The Colt Commando was very popular because of its lightness and ease of transport. It was a weapon used by radio operators who needed a lighter rifle, and by officers.

Above: The initial model of the M-4 rifle, was different from that used today with its carrying handle sets, with copies of today have a removable handle ..
Below the 2 copies of the M-4 SOPMOD A3, actually in use by special forces of the United States. The rifle down, has a laser sight system and a micro-camera installed on the small side frame tile, used to the soldier to practice what we call indirect fire, where the soldier is hiding in some obstacle like a corner of a building, for example, and exposes only the gun, than with a camera mounted, allows the soldier visualize, aim and shoot unerringly, to expose more than their own hand.

Below, an M-4 carbine A3 with his M203 grenade launcher. It is also very common to use this model in action by the troops in urban combat in Iraq and Afghanistan.

In 1985 the U.S. Marine Corp or Marine Corps of the United States commissioned a version of M-16 A2 which is smaller, and that the Colt Commando was used as a base, though his pipe should be higher than the Colt Commando, and thus the length of 14 inches and a half. This new version is called M-4 and it is extremely common in American forces in combat in Afghanistan and Iraq. Although the M-4 carbine is called, he also holds the position of fire burst. Today the more modern version in production is the M-4 A3, which has shot selector with short bursts of 3 shots, and removable carrying strap.
The evolution of the AR-15 in those 44 years of existence has greatly improved the reliability and efficiency of this weapon, and the new versions are modular weapons with easy mounting of accessories and with good accuracy.

For the future there is a tendency to adopt a new caliber rifle for the U.S. armed forces. After 4 decades, some concepts have changed on the battlefield and 5.56 mm, has raised criticism by American soldiers has been struggling to overthrow the Iraqi and Afghan guerrillas, with only one shot in the chest, and often when the enemy is far, the American soldier has had to shoot a second time to “stop” the action of the enemy. The gauge most likely to be incorporated, is the 6.8 mm SPC (Special Purpose Cartridge), which has the same length of 5.56, but is somewhat broader. This gauge has been tested in combat in Afghanistan and the result was considered very good by the soldiers. It was recently changed the SS-109 missile, which NATO was standard for a greater weight, somewhere around 70 grains, which showed an improvement in mortality, but this subject is open, and no decision has been made.

Above: In this photo two specimens of M468, a version of AR-15 caliber 6.8 mm SPC, made by Barrett, known for making large-caliber rifles in 50, as the M-82.