MARINE CORPS AIR STATION MIRAMAR, Calif. -- Although the U.S. military has gone through several different rifles in the last 200 years, throughout its extensive history the M-16 has been the longest lasting, issued service rifle for all branches of the United States military.

The original XM16E1 assault rifle was designed in 1957 by Eugene Stoner, a Marine Corps veteran, as a response to the use of the German Sturmgewher, a rifle that could fire medium sized bullets over a long range at high speeds during World War II.

U.S. Secretary of Defense Robert McNamara halted the production of the M-14 in 1964 and the U.S. Army ordered 85,000 of the XM16E1 for experimental use and was pleased with the result.

They started calling it the M-16. The Air Force then officially accepted its first 19,000 United States Rifle, caliber 5.56 mm, M-16, a modified version of the AR-15, as found on www.wikipedia.org.

The rifles the Air Force received were slightly different than the ones the Army was experimenting with, because it had no forward assist on it. The forward assist is used to push a round into the chamber during a reload in case it is stuck in the chamber due to a build up of carbon.

By 1965, the M-16 received so much attention that most of the flaws the Army reported had been fixed. At this time, the M-16 was being introduced in high numbers. However it did not perform to the soldiers' standards while using it in combat and soon gained a bad reputation.

The Pentagon had stated they wanted all the ammunition to be made with the new, finer grade ball powder. This did not coincide with the claim that Colt Industries made saying the rifle never had to be cleaned. The reason is the new powder was much dirtier than the old powder used in ammunition.

After Colt installed forward assists on all versions of the M-16, against the advice of Eugene Stoner saying that it would just complicate the use of the weapon, a second version of the rifle was created and called the M16A1 service rifle. This new model, however, still had its problems because soldiers were told once again that this new model never had to be cleaned due to its space-aged construction. When the weapons started jamming during field use the debates over the M-16 were once again re-opened throughout the U.S. military.

This was quickly solved by the production of cleaning kits and cleaning instructions that were distributed to the soldiers. This made the M16A1 work more efficiently and the complaints about the rifle soon came few and far between.

In 1977, with armor improving throughout the world, the U.S. military started to complain about the low penetration that the current ammunition had. After tests of different styles of ammunition made by several countries, the Belgian SS-109, a 5.56 mm round based off the U.S. cartridges, was finally accepted. The only difference with this round was that it had a steel tip. Only one drawback was reported - the round had to be developed with a 1-in-7 barrel twist rather than the 1-in-9 twist the M16A1 had.

This change brought one of the most current models of the M-16 to the U.S. military. The M16A2 service rifle that has been used without major modifications over the past 25 years.

This model has many features that the others did not such as vented hand guards that keep the barrel cooler, a re-designed bolt carrier group that allows for a smoother firing round and a hollowed buttstock the field cleaning kit can be stored in.

"The rifle is still very temperamental and jams frequently which could be the difference between life and death on the battlefield," said SSgt. John P. Vera armory staff noncommissioned officer in charge, Headquarters and Headquarters Squadron, Marine Corps Air Station Miramar.

With a long reign of service, the M16 has seen its share of battlefields and drill movements, raids and range shooting and will go into the history books as one of the most important weapons that changed the face of modern warfare.