The M16 has had a remarkable history. From a tiny 9-person company back in 1954 to nearly having its reputation destroyed early on in Vietnam to dominating battlefields for over 60 years and being USED TO FIND BUBBA. BUT WHAT MOST people don’t know is that technically the British SAS were using the rifle before the US Army officially adopted it.
And while you might know it’s a great rifle, I bet you don’t know every genius detail. From the jungle to the desert and everywhere in between, the military and cultural phenomenon that is the M16. By the 50s, the legendary M1 Garand was getting on a bit, and its replacement, the M14, had problems. It was long, heavy, and too ludicrously overpowered to control on full auto.
Enter Eugene Stoner, an aerospace engineer with no formal engineering qualifications. But what he lacked in credentials, he made up for in pure genius. In 1954, Stoner joined the tiny Armalite division of Fairchild. Just nine employees. Then came the AR10. His 7.62 mm battle rifle unlike anything ever seen. aluminium receivers, fiberglass furniture, straight line stock, a direct impingement gas system, sort of. We’ll come to that later.
At just over 6.85, it was over a pound lighter than its competitors. It’s so hard to delete from our minds the image of the AR10, 15, M16. to delete that from our minds and really appreciate just how space age this thing looked in 1954 before the space age had really kicked off at all. The AR10 was submitted to the 1957 Abedine trials against the T44 and the FN foul.
But here’s where things kind of went pear-shaped. Armalite’s president insisted on fitting an experimental barrel against Stoner’s objections. During testing, it burst. The army chose the conventional T44, which became the M14. But the AR10 lost the battle, but kind of won the war. It established the elements that would define every AR style rifle that would follow.
Lightweight materials, direct impingement is, we’ll come to that later, straight line stock, rotating multi- lug bolts, and the general layout. So in 57, Stoner and his team rescaled the AR10 down to fire the new 223 Remington round. The result, the AR-15 or Armalite 15. By 1959, Armalite was skint and sold the rifle’s rights to Colt for $75,000 plus royalties.
Perhaps one of the worst business decisions in firearms history. Air Force General Curtis Lé saw it demonstrated at a 4th of July party in 1960 where Colt had set up watermelons as targets and he ordered 80,000 of them. Then came Vietnam. The dense jungle exposed everything wrong with the M14, only highlighted further by the fact it was going up against the AK-47, the Soviets take on the assault rifle concept.
So, in 1963, pretty much desperate for more rifles to use in the war, the army finally adopted the AR-15 as the M16. Stoner’s vision was finally vindicated, and the M16 was born. What makes it special? The genius of the design. Stoner’s aerospace background gave him a completely different approach to most other gun designers.
He fought like an engineer designing an aircraft where every gram matters, but everything must work. Aluminium receivers and polymer furniture were genuinely radical in the ’60s. Most rifles still used wood and thick, heavy steel like they were built in a Victorian workshop. The 5×6 cartridge was another stroke of genius. Soldiers could carry around three times more ammunition for the same weight as 7.62.
The straight line design meant the recoil went straight back into your shoulder rather than rotating the muzzle up. But here’s the real genius trick at the heart of the rifle, the gas operating system. Although commonly referred to as being a gas impinchment rifle, that’s not technically right. Gas impinchment would refer to gases pushing the bolt back.
That’s not what’s happening here. Gases are tapped off from the barrel, sent along this gas tube into the bolt itself, where it presses on the gas piston and unlocks the bolt, sending it to the rear, cycling the action before the gases are expelled through the side of the bolt itself, which is incidentally why you can’t bulp an M16 design.
The gases coming out the bolt are sometimes unpleasant enough as it is. Bull pup the thing and it’d be right by your eyeball. And with this handguard split, you can really see how little is in here. It’s just a barrel and one fin tube. No complex gas parts up front. Whereas on something like an S80 L85, which in itself is a copy of another stoner design, the AR18, there’s a lot more going on up in here.
And then, as if the design isn’t genius enough already, there’s dualpurpose engineering going on. Pretty much every part is doing some kind of double duty. Like how the pistol grip is actually holding in the selector switch spring. The barrel nut secures the barrel and the handguard at the same time.
The bolt carrier is the gas piston. The buffer tube houses the recoil system and it attaches the stock. Carry handle is the rear sight. Front sight is the gas block. Stoner’s amazing less is more approach. Means the M16 uses about 100 parts total. About half as much as something like well this forbidden thing. And by pressing out a couple of pins in just a few seconds, you can change the configuration entirely, much to the ATF’s dismay.
The result is an elegant, efficient design that’s been copied for over 60 years. It’s pure engineering brilliance. And yes, I know this replica has the wrong flashhider. It bothers me greatly. Vietnam, the disaster that almost killed it. When the M16 reached Vietnam in 1965, it was kind of rushed into service. And what happened next nearly destroyed the rifle’s reputation forever.
The first scandal, the ammunition. Stoner had designed the AR-15 around Deont’s IMR 4475 powder, which burnt cleanly. But the military, in their infinite wisdom, switched to Olan Mat’s WC846 ball powder. It produced the right velocity, but burnt filthy, leaving thick fouling residue throughout the action.
The second scandal, no cleaning kits. Troops were told the rifle was self cleaning, which is the biggest bit of believing the BS hype that I’ve ever heard of. The result was kind of catastrophic. The M16 would jam almost constantly during firefights. Soldiers were found dead next to disassembled rifles where they tried to repair them midfirefight.
The Battle of Hill 881 in April and May of 1967 was the rifle’s darkest moment. Marines pinned down on a hilltop with rifles that simply wouldn’t fire. The 1967 IICORD subcommittee investigation found that the failures were borderline criminal. Blame was placed firmly on army ordinance who had ignored Stoner’s specifications without proper testing.
The fixes came thick and fast. Chromeline chambers and BS, cleaning kits issued to every soldier, proper ammunition, better training. Suddenly, the M16A1 was born, and that thing really worked. But a lot of damage had been done, and the M16’s reputation took decades to recover, going global foreign adoption. While US troops in Vietnam were struggling with their M16s, another military had quietly adopted the rifle and loved it.
In 1962, the British SAS purchased Colt Model 602s for use in the Indonesia Malaysia confrontation. Yes, the SAS was using the M16 before the US Army officially adopted it. Why? Well, because the SAS needed something lighter than the L1 A1 SLR for jungle warfare in Borneo. Something with full automatic capability, compact, lethal in close quarters.
The AR-15 fit the bill perfectly. Beyond Britain, the M16 spread like wildfire. South Korea, the Philippines, Australia, Singapore, Israel, Canada. By the 2000s, over 90 countries were fielding the rifle. In total, there’s over 8 million of the things around the world, not including the M4 and civilian AR-15 variants. Cultural domination.
But the M16 didn’t just dominate battlefields, it conquered popular culture, too. Full Metal Jacket showed us the brutal reality of Vietnam with the M16 featured heavily. We Were Soldiers dramatized the debut of the M16 in Vietnam. Forest Gump introduced the M16 to a younger generation. Bravo 20 featured Shaun Bean as Andy McNab, carrying M16 A2s with M203s during the SAS Scud hunting mission.
Blackhawk Down showcased the A2 and A4 in more modern combat. Apocalypse Now, Hamburger Hill, Tropic Thunder, Tears of the Sun, Lone Survivor, American Sniper, 13 Hours, Jarhead, Three Kings, Heartbreak Ridge, Predator. Oh, and of course, the Blues Brothers. On television, you had the A Team constantly firing or being fired at by M16s and no one ever hitting a damn thing.
Oh, and then there’s uh For all mankind, because nothing says realistic alternative history like astronauts shooting M16s on the moon. And then video games. Call of Duty: Modern Warfare introduced a whole new generation to the M16 and especially the holographic site. Counterstrike features the AR-15 family across its loadouts. The Battlefield series used the rifle everywhere.
There’s Rainbow 6, Ghost Recon, Medal of Honor, Armor, Far Cry, Insurgency Squad, Hell Let You Loose, Rising Storm, Vietnam Escape from Tarov, Fallout, GTA 5, and countless, countless others. From hyperrealistic military simulations to arcade shooters, it’s everywhere. Generations of gamers have leared to love the M16. Significant events.
Here are just some of the rifles significant moments. November 65, the Battle of Lrang. The M16’s combat debut. April to May 1967, the Battle of Hill 881. The rifles darkest moment leading to the Icord subcommittee investigation. May 82, the Fala’s War, Pebble Island raid. The SAS used M16s with M203s to destroy 11 Argentine aircraft.
October 93, the Battle of Moadishu. M16 A2s in brutal urban combat immortalized by Blackhawk Down. 97. The North Hollywood shootout. LAPD officers desperately outgunned having to go shopping for AR-15s. November 2004, the Battle of Fallujah. ACOG equipped M16 A4s used for precision headshots in urban combat. The variants.
The M16 of course evolved over its 60-year service life. The original model we’ve already discussed. Then there was the M16 A1 updated during the Vietnam era. But apart from the Ford assist, it’s externally pretty much identical to the original M16 model. Then the A2 arrived in 1983, adding free round burst, a heavier barrel, and improved sights, but it kept the fixed carry handle and fixed stock.
Then there’s the M16 A3, which was a full auto navy version of the A2. Then the M16 A4 brought the rifle into the modern era with a flat top receiver, removable carry handle, and a Pikatini rail system. And of course, the civilian AR-15 market just exploded after cult patents expired. Today, there’s an estimated 24 million at least in private hands worldwide.
The limitations of the M16, but the M16 wasn’t perfect. Hear me out before you freak out in the comments. For instance, the buffer tube sticking out the back of the receiver makes folding stocks almost impossible without some serious modifications. for the platform is almost, but not quite ambidextrous. You can certainly do almost everything you need to do left-handed, use a selector switch, whatever you need, but it is a slightly different manual of arms.
In fact, in some ways, the rifle works better left-handed, especially bolt hold opens. Trying to do that as a right-handed user, and it’s kind of a little bit awkward, especially if I was in the prone. And you’re not going to be dropping mags super quickly. There’s just no way to reach it for a lefty.
You’re going to have to rip them out using the offh hand. Heat dissipation can be an issue, although as many a meltdown has proved, you’re never going to cook the thing with a normal combat loadout. Suppression can be a really interesting topic, as you’re already pumping gases back into the heart of the beast, as it were. The extra back pressure from a suppressor can really increase that and cause some issues. So, it has to be tuned.
Yes, I know. Short stroke gas piston versions do exist that solve all of this, but that’s a major platform change and not really an M16 anymore. The 39 in overall length does make it just a bit cumbersome, especially in vehicles, helicopters, or urban combat. The gas system is genius. And expelling the gas out the side of the bolt before it travels fully backwards is genius.
And it keeps most of the fouling out, but not all of it. Whichever way you put it, there is still burnt propellant gas going through the bolt in the very heart of the rifle. Auto rifle, as some people say, it poops where it eats. And I just want to throw this one out there because I know I’m going to get hate for it, but I’m just going to say it.
The index finger mag release is amazing for living out our Jerry Mitchell operator fantasies of being able to change mags in like one or two seconds. It’s fantastic. However, the thing is sometimes there are situations where being able to get the mag out with just your left hand, say the rifle’s laid down, sometimes you it would be nice to have a mag release on the left. That’s all I’m saying.
And if you come from any other rifle, literally any other, whether that’s SA80, an MP5, an AK, you’re so used to using your left thumb to release mags, this does feel a bit strange. Okay, it is fun. The rise of the M4, how the M16 got replaced. Let’s talk about the M16 successor, or should I say its child. The M4 Carbine was adopted in 1994 as a shortened M16.
Yes, I did say carbine, not carbine. I’m English. It shares 80% parts commonality with its parent rifle. Originally, the M4 was meant for support troops, vehicle crews, and special forces. It was never actually intended as the main service rifle, but the global war on terror changed everything. Urban combat in Iraq and Afghanistan demanded shorter, more maneuverable weapons, and the M16’s 39in length kind of a liability when clearing buildings and operating from a vehicle.
Improvements in the ammunition closed the gap between the M16 and the M4. The longer barrel not having such a big advantage. The US Army began phasing in the M4s as their standard rifle from 2010. The Marines switched in 2016. Plenty of rifles have tried to replace the AR-15 M16 platform entirely, but most have failed spectacularly.
The XM8 program in the early 2000s was HK’s polymer rifle designed to replace the M16, and it was cancelled in 2005. The XM29 was just too complex, too expensive, and it was abandoned. Some elite forces tried the FN SCAR in the late 2000s, but most operators went back to the M16 or M4. The M16 platform is just already well too good and too established.
Decades of training, billions in logistics, and the entire production line built around this design. The sunk cost is staggering. So, what’s next? The next generation squad weapon program has seen the Sig XM7 or now M7 and M9 6.8 mm being adopted to replace the M16 and M4 platforms in some units. But the M7 certainly has its critics.
Heavier, more recoil, less ammo capacity, and significantly more expensive with many soldiers preferring their M4s. The 5.56 mm has incredible staying power. The logistics, the training, the ammunition stockpiles built up over 60 years. They aren’t going anywhere fast. The M16 earned its incredible reputation through trial by fire.
The Vietnam disaster nearly destroyed it, but became its defining redemption story. Three generations of soldiers have carried the rifle into battle. It’s the most copied rifle design in history, going from near disaster to the gold standard, the defining American rifle of the modern era. Even though it’s been replaced by its M4 child, the M16’s legacy is undeniable.
And even with the HK 416 seeming to dominate the world with its piston upper, there’s no denying that the M16 is the 5.56 rifle that started it all. If you enjoyed this video, then like, subscribe, and check out this video here for more great military content.
