Key Points – The M4 carbine, a compact derivative of the M16 rifle tracing its roots to the Vietnam-era CAR-15, became the ubiquitous weapon for US military personnel (Special Operations, infantry, Marines) throughout the Global War on Terror.
-Its lighter weight (around 7.3 lbs) and shorter barrel (14.5 inches) made it ideal for close quarters and airborne operations, though its ~500m effective range highlighted a need for Designated Marksman Rifles.
-After over two decades of distinguished service in Iraq, Afghanistan, and elsewhere, the 5.56mm M4 is now being replaced by the SIG Sauer XM7 under the Next Generation Squad Weapon program.
What Is So Special About the M4 Carbine?
For all the AR-15 aficionados out there, this article is for you. You love to hold it and shoot it, then clean it up and do it again.
So why did the AR-15 become so popular with civilians?
Look no further than the M4 carbine that dominated the enemy during the Global War on Terror.
You never saw a special ops member, infantry soldier, or marine without an M4 Carbine for the last 20-plus years.
It became so ubiquitous that civilians wanted one too.
What Was the CAR-15?
The M4 Carbine dates back to the Vietnam War when the Long-Range Reconnaissance Patrol soldiers needed a weapon that was compact and still semi-concealable so they could snoop deep into enemy territory without being seen. This was the CAR-15, the older brother of the M4. The M-16 was longer and cumbersome in close combat situations, so special operations personnel later preferred the smaller size of the M4, especially when they jumped out of airplanes.
The M4 then spread to light infantry units later in the 1990s. Some soldiers and marines still used the M-16A2 and A3 until the Second Gulf War and you can see photos of marines still using the M16A4 in combat as late as 2004.
My Experience with the M16 and M4 Carbine
I served in the U.S. Army from 1999 to 2004. This meant that I used both the M16A2 and the M4 Carbine. I actually preferred the M16A2 – probably because it was the rifle I learned to shoot with in the Army at Basic Training at Fort Knox, Kentucky. I also had longer arms and the M16A2 was more comfortable for a long, lanky guy like me.
The first time I saw the M4 was during my service with the 19th Special Forces Group at Fort Irwin, California, in 2000. The Special Forces guys preferred the weapon when conducting airborne operations. I was not Special Forces qualified; I was simply a military journalist attached to the Green Beret unit, but I used the M16A2 during that training iteration at the National Training Center, not the M4.
I Had a Choppy Transition to the M4
Later, I became an infantry officer serving in the Republic of Korea near the DMZ at Camp Casey in 2001 before 9/11. I must admit the first time on the range with the M4 was not a success. I used iron sights, and the M4 had a muzzle velocity different from the M16A2. I couldn’t get a good sight picture with the M4, and my cheek-to-stock weld technique wasn’t comfortable because of the collapsible stock. Though the M4 felt good in my hands, I slowly adjusted. Plus, we used one of the early close combat optics that were better than using iron sights.
Designated Marksman Rifle
One time during training, I recognized that with many members of the infantry platoon carrying M4s, a longer-range shot from the best marksman in the platoon was not possible with the smaller weapon. I thought that at least one soldier in the unit should carry an M16A2 or A3 to engage longer-range targets.
The Army slowly came around to my way of thinking and introduced the Designated Marksman Rifle for those who needed extra range. It could engage targets at ranges of 300 to 600 meters in the sweet spot between an M4 and a sniper rifle.
Quick Look at M4 Specs
The M4 fires a 5.56mm round. Personnel typically use a 30-round magazine. The M4 is lighter than the M-16 at around 7.3 pounds. This is another selling point for the M4. The M4 is only 33 inches long with the buttstock open. The barrel length is 14.5 inches, and the maximum effective range, depending on the personnel’s skill, is usually around 500 meters.
The M4 served its country well for the last 20 to 25 years. Now, it is being replaced by the Sig Sauer XM7 rifle based on the Next Generation Squad Weapon project. The M4 will hold an esteemed place in military history as the weapon of choice for personnel serving in Iraq and Afghanistan. If you served in those days, you probably learned to shoot with the M4 and used nothing else during your service. If you were in the armed forces like I was (in between the war in Kosovo and the Second Gulf War), you may have shot both the M-16A2 and the M4. Both had their advantages and disadvantages, and both are still memorable.
About the Author: Dr. Brent M. Eastwood
Brent M. Eastwood, PhD, is the author of Don’t Turn Your Back On the World: a Conservative Foreign Policy and Humans, Machines, and Data: Future Trends in Warfare, plus two other books. Brent was the founder and CEO of a tech firm that predicted world events using artificial intelligence. He served as a legislative fellow for U.S. Senator Tim Scott and advised the senator on defense and foreign policy issues. He has taught at American University, George Washington University, and George Mason University. Brent is a former U.S. Army Infantry officer. He can be followed on X @BMEastwood.
This piece is recirculated due to breaking news about the M4 Carbine’s replacement.
