whats the differance ar15 m16?

AR-15 is an all encompassing term that covers any and all firearms based on the mechanics laid out by Eugene Stoner on the rifle he termed AR-15 when the applied for patents etc.

The US military ordered some AR-15s made and they had some very specific requirements about features, barrel length, handguard shape, etc etc. The military termed those AR-15s M-16.

Later the US military wanted some different features such as a heavier barrel, chrome lining, different shaped handguard, etc etc. The military termed those AR-15s M-16A1

The Canadan military liked what they saw and wanted some AR-15s too. They put down their specific requirements (which was pretty much the same list as the M-16A1 but with a few minor changes) and called that type of AR-15 the C-7

The the US military wanted a shorter version, so they put down their requirements and that type of AR-15 was called the M-4.

Now many gun companies make AR-15, each having it's own name based on what features are present and basically whatever the company wants to call it. These are available in gun stores for civilians to purchase. These are ALL AR-15s no matter how different they are from eachother.

The key is that a gun is a machine. It is defined by how it works mechanically in a very specific way.

For a gun things like barrel length and type of stock are like what kind of stereo, tires, and color a car is. Changing stereo, tires, and color doesn't change what kind of car it is.

an ar 15 is a legal model of the m16 assault rifle. it is semi automatic and uses .223 or 5.56 ammo. Some people may say that they are selling a m16 but if itis semi its just a m16 modeled ar15. M16 are still used by military and were first used in vietnam war. you can buy a m16 but it is expensiv and you have to have a license to buy one and know where to find one.

One is automatic, the other isn't. An AR15 receiver there are a couple holes not drilled or in different positions to make an auto sear impossible to put in and the trigger setup is also different.

ar 15 are commercial semi auto rifles. m16 are select fire military rifles. ar 15 don't have auto sears.there bolts are also different.you can buy an ar 15 in a non commie state and you also can buy a m16 but it is going to cost thousands because there receivers are very valuable.hope you don't live in a commie state