This is such a great question! What is the difference between AR-15, M-16s and M-4s? We found that 80% Arms provides a precise/concise answer to this question.
Let's start with reviewing the fact that there are civilian and military designations just to start the conversation.
What are AR-15s? The AR-15 can be traced back to when Armalite and Eugene Stoner designed a lightweight, gas-powered, selective-fire rifle for the United States Military. They sold their design to Colt in 1959, as well as the rights to the names AR-15, and AR-10. It is the most popular rifle in America, with an estimated 10,000,000+ in civilian hands. It is “America’s Rifle”, and their design ranges from the Pistols to SBRs.
What are M-16s? The M-16 was manufactured by Colt and shipped to troops overseas in Vietnam. It has become the most common military weapon of all time. The rifle has developed over time to suit the constantly advancing and adapting needs of our warfighters overseas. The most recent adaptations allow optics to be added and selective firing (Semi/Full Auto, and Semi/Burst). Nonetheless, the M-16 has kept the a 20” barrel which is a weakness of design when in battle or even in urban areas.
What are M-4 Carbines? The weakness of design of the M-16 birthed the creation of the M-4 as its compact nature allows for easier use in urban areas and in vehicle transport scenarios.It has now been adopted by all US Armed Forces.
What is the difference between the AR-15 and M-16? 80% Arms explains this perfectly
"the easiest way to look at it is this: Every M16 is an AR15, but not all AR15s are an M16...some versions are semi-automatic, some are full-automatic...but, the most noticeable difference is that the civilian AR15 lower receiver does not have the third trigger pin hole for the auto sear above the safety selector. The trigger pocket is also typically milled to different dimensions to prevent the acceptance of an auto-sear as well. However, this is not a rule. Many companies still sell their lowers with M16 trigger pocket dimensions, they are just missing the proverbial "third-hole". Drilling that third hole is what legally changes your AR-15 from a semi-automatic rifle, into an illegal machine gun."
Well there you go folks, that is the main difference that 3rd hole which changes a semi into an illegal machine for civilians. What is your opinion? We'd love to hear from you!
