Key Points: The M4 Carbine, beloved by civilians and military personnel alike, owes its popularity to its combat success during the Global War on Terror.
-Derived from the CAR-15, the M4 offered compact size, maneuverability, and adaptability, becoming a staple for U.S. forces by the 1990s.
-Firing 5.56mm rounds with a 30-round magazine, the M4 was lighter and more versatile than its predecessor, the M16, with a maximum effective range of 500 meters.
-While the Sig Sauer XM7 is set to replace it, the M4 holds a storied legacy as a reliable and indispensable weapon during pivotal modern conflicts.
The M4 Carbine: Lightweight, Lethal, and Legendary
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.
Sgt. Jacob Harrison, a U.S. Army Reserve Soldier from the 377th Theater Sustainment Command, takes aim with his M4A1 carbine at the M4 Reflexive Fire event during the 2021 U.S. Army Reserve Best Warrior/Best Squad Competition at Fort McCoy, Wis., May 22. Approximately 80 Soldiers from across the nation travelled to Fort McCoy to compete in the annually-recurring event running May 19-28. It brings in the best Soldiers and squads from across the U.S. Army Reserve to earn the title of “Best Warrior” and “Best Squad” among their peers. Competitors are evaluated on their individual and teamwork abilities to adapt and overcome challenging scenarios and battle-focused events, which test their technical and tactical abilities under stress and extreme fatigue. (U.S. Army Reserve photo by Staff Sgt. Christopher Hernandez/Released)
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.
U.S. Army Sgt. Benjamin Rodgers, assigned to Bravo Troop, Regimental Engineer Squadron, 2d Cavalry Regiment, provides security during Exercise Allied Spirit V at the 7th Army Training Command’s Hohenfels Training Area, Germany, Oct. 4, 2016. Exercise Allied Spirit includes about 2,520 participants from eight NATO nations, and exercises tactical interoperability and tests secure communications within Alliance members and partner nations. (U.S. Army photo by Visual Information Specialist Gertrud Zach)
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.
Jonathan Shue, machine shop noncommissioned officer-in-charge, Marine Aviation Logistics Squadron 36, Marine Air Group 36, 1st Marine Aircraft Wing, III Marine Expeditionary Force, shoots his M4 carbine here May 10 at the 2011 Australian Army Skill at Arms Meeting. The meeting is an annual, international combat marksmanship competition hosted by the Australian Army that will be held through May 19. (U.S. Marine Corps Photo by Lance Cpl. Mark W. Stroud/Released)
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.
