What is the AR15
The AR15 is a highly customizable rifle used by the civilian class. There are multiple calibers that fall under the name AR-15. The most popular is the 5.56 NATO round, very similar to the .223 Remington. For simplicity, a .22 caliber round with some kick. As stated before, this is a gun platform that is highly customizable. There are very many different calibers that the AR15 can come in. For example, I will be building a 6.5 Grendel soon and I have a 5.56 NATO and a .22lr all which are AR15’s.
I stated earlier that the AR-15 is a civilian class rifle. The AR-15 chambered for 5.56 NATO is the United States military M16 rifle. The M16 is an automatic weapon where the AR-15’s are semi-automatic. If you do not know what the difference is, a lot of what I said so far probably does not make a lot of sense.
AR-15 simply means ArmaLite model 15. Some will tell you it means “assault rifle” or “automatic rifle”. Both of those are incorrect though. Although ArmaLite does not own the rights anymore more the name is still used.
Creators of the AR15
The AR-15 is actually based of the AR-10. The AR10 is a larger caliber rifle, the original was 7.62mm. Eugene Stoner created the AR10 while working at ArmaLite and in 1956 it was submitted to the United States Army for testing. At the time, the U.S. Army was looking at replacing their current rifles because research showed that the majority of casualties and injuries occurred within 300 yards. By changing to a lighter rifle, not only did the U.S. Army lighten the load for the soldiers but it also made them more efficient in combat.
Unfortunately, the AR10 was submitted late and did not make the cut for the military forces at the time. The military did ask to have the AR10 changed over to a lighter round. ArmaLite had financial difficulties and sold the rights of the AR platform to Colt. Colt has trademarked AR15, or AR-15, and officially AR-15 actually means a Colt product. Although, the only people who probably follow this are the Colt fanatics. The United States Air Force was actually the first division of the armed forces to begin using the M16 in 1962. Followed by the Army in 1965.
The AR-15’s rough beginning
The AR15 was designed for its cartridges to use IMR propellant. This burns cleaner and more efficiently than other powders that were used prior. The M16 had been advertised that it would never need cleaning – a rumor that I do not know how anyone would believe if this was advertised.
During the Vietnam War, the production of ammunition was very hard to keep up with orders. Instead of using the IMR propellant that that the M16 (AR15) was designed to use, ball powder was used instead. This led to a great deal of fouling, which led to jamming and other malfunctions. Once the issue was discovered, cleaning kits were issued and the ammunition was made to specifications eventually too.
M16 to M4
The United States armed forces started using the M16 in 1962. This service rifle has been very effective to date. The military is changing over to the M4, which is still on the AR platform. The differences are that the M16 has a 20 inch barrel, is more accurate at longer ranges, has a rigid stock, and plastic stock. Where as, the M4 has a 14.5 inch barrel, a collapsible 6 position stock, and is better for close combat in confined spaces. Overall, the differences are changing from a rifle that shoots medium distances to a rifle that is build for closer spaces.
The M4 would perform better for building raids and such, and the M16 would perform better with a more open battle field. And a bullet will travel 25-30 feet per second per inch of barrel. So this 5.5 inch difference in barrel length changes the feet per second by roughly 138 feet per second. For entering buildings and maneuverability the M4 would be a better rifle.
The modern AR15’s biggest issue is all the options that there are to make one. Do you want a free float tube or a quad rail, what type of grip do you want, how long of a barrel, what caliber, flat top or handle top, decorated pins or dust cover, and the list goes on for quite awhile. Overall, the biggest question is, “What are you using it for?” My 5.56 is for plinking and some varmints mainly. I can hit the head of a screw at 100 yards and I have fun with this rifle. The .22lr is for plinking and small game, such as squirrels. And the 6.5 Grendel is going to be for coyotes, deer, just shooting, and much more.
If you are getting an AR15, know what you will use it for. If you are wanting to shoot 1,000 yards, you won’t be using a 5.56 with a 16 inch barrel. If you will only be shooting up to 300 yards this could be a good gun. Also, the twist of the barrel matters with the grain of the cartridge. As you can tell, there are a number of options, I did not mention many of the options that are out there or the different categories of options.