A Look Into The Rare HK 416 Rifle

Trigger Time on The Gun Used To Kill Osama Bin Laden

February 05, 2025 By Will Dabbs, MD

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Never underestimate the simply breathtaking power of random. At just past 0100 on May 2, 2011, about two dozen exquisitely-trained US Navy SEALs assaulted Osama bin Laden’s covert compound in Abbottabad, Pakistan. A decade after the horrendous Al Qaeda attacks on 9/11, these members of the US Naval Special Warfare Development Group (DEVGRU) stood ready to kill the most hunted man in the world. Operation Neptune Spear was the culmination of a decade’s worth of frenetic intelligence work.

Clearing hostile structures is one of the most dangerous missions any modern combat unit might perform. Military formations like DEVGRU and the US Army’s Delta Force have raised it to an art form. These tooled-up operators move through a structure with a ballerina’s grace, killing or capturing Bad Guys while securing vital intelligence materials. As with most such things, there’s a choreographed method to it all.

HK 416 next to ArmaLite AR-180 — The HK416 drew inspiration from the ArmaLite AR- 180 shown on top. (Photo Provided by Author)

Intelligence concerning the internal layout and condition of target structures is always an inexact science. As such, these operators are trained to peel off as necessary to deal with prisoners, secure intelligence materials, provide security, or just address unanticipated chaos. As a result, it was random math and simple fate that had a small group of Navy SEALs including Rob O’Neill pushing into bin Laden’s third-floor bedroom.

The details remain controversial given the obviously classified nature of the operation. However, the generally accepted version of events was that the lead SEAL shot one of bin Laden’s bellicose wives named Amal Ahmed Abdul Fatah in the leg. He then threw himself across the woman to shield his mates in the event she was wearing a suicide vest. What a stud. At some point O’Neill shot bin Laden twice in the forehead with a pair of 77-grain Open-Tipped Match 5.56x45mm NATO rounds from his HK416 assault rifle.

If ever there was anybody who just needed killing it was that guy. The chaos and heartache he sowed literally spanned the globe. The rifle that Rob O’Neill used to send this diabolical vermin to meet his seventy dark-eyed virgins is itself a rarefied piece of kit.

The HK416

The HK416 was originally supposed to be called the HK M4, but Colt filed a lawsuit. The 416 was the result of a mind meld between the US Army’s Delta Force and Heckler and Koch. Larry Vickers was the R&D NCO for Delta and the point man for the project from the Army side. HK drew on their experience producing the G36 and the ill-fated US Army XM8 as well as the upgrades they had performed on the UK’s fleet of SA80 bullpup rifles. Delta ultimately replaced its M4’s with HK416’s in 2004.

HK 416 with Combat Helmet and Grenade — A homebuilt DIY HK416 is the apex predator among Information Age Modern Sporting Rifles.(Photo Provided by Author)

The biggest departure from the M16 is the short-stroke gas piston that drives the action of the HK416. Derived predominantly from the action of the ArmaLite AR-18 rifle developed in 1963, this mechanism keeps carbon fouling and heat out of the gun’s entrails. It’s also fairly heavy. However, this makes for one supremely reliable firearm.

I spent eight years in uniform as an Army Aviator. I wasn’t anything special, but I got to work with some truly extraordinary folks. One Delta buddy did seven combat tours with The Unit. He once told me that he would start a four-month deployment with a spotless HK416 and shoot almost every night. He said he wouldn’t do any serious cleaning or maintenance to his rifle until they got back to home station.

How Do You Get One of These Guns?

Heckler and Koch is an interesting company. I always thought they just didn’t like money. Though they make some of the finest firearms on the planet, they have never really bent over backwards to sell their most rarefied wares to normal folk like us.

I have been told this is due to some kind of weird German export restrictions. I have also heard that it is because they are stuck up and just hate everybody. No telling and no matter. However, it is a truly epic challenge to land a genuine HK416 of your own.

HK sells a semiauto version of the 416 called the MR556. The MR556 is indeed a superb piece of kit. However, it sports a 16-inch barrel and costs as much as a nice used car. As I was looking to replicate the gun Rob O’Neill used to off bin Laden my quest went somewhat farther afield.

I’m not the only guy in America who wants one of these things, so that makes for a curious market. HK will sell most anything to Law Enforcement agencies, but the BATF and HK both frown upon cops obtaining these weapons for subsequent sale to civilians. All of the current-production HK416 rifles are selective fire and therefore obviously restricted to government or LE organizations. Right, wrong, or otherwise, them’s the rules. However, you can remove the parts of an HK416 from its registered full auto lower receiver, and they become nothing more than a pile of uncontrolled gun components. That’s how I got mine.

HK 416 on Hood of Humve with Combat Helmet — The HK416 is indeed a superlative combat rifle. (Photo Provided by Author)

Mississippi Auto Arms is the coolest gun shop in the world. I justifiably consider myself a bit of a connoisseur of such places, and nothing I have ever seen even comes close. The shop is modest, but they also have a robust online presence. MAA is always working deals and trades with LE agencies wishing to upgrade their surplus firearms. It was through a deal done with the Kansas State Police that the good folks at MAA came into a small supply of HK416 rifles.

My gun sports the short 11-inch barrel and early features. As part of this deal I also landed one of the stubby Surefire suppressors that came from the same State Police SWAT team. My Surefire can looks like it was rescued from a house fire and has an ample dent in the side yet nonetheless runs like prunes through an infant.

In a lifetime of gun collecting, I have landed precious few truly epic bargains. More commonly I lay my sights on something blued and oily without which I simply cannot live and then do whatever it takes to make it my own, sometimes hemorrhaging cash in the process. It’s honestly a tribute to my wife’s remarkable wisdom and leavening influence that I own an automobile, have a roof over my head, and do not scurry about impoverished wearing nothing more than an improvised loincloth. However, back in 1987 there was a singular gleaming exception.

I bought my transferable full auto M16 lower receiver from the pages of Shotgun News, the previous title of the esteemed periodical you currently seem to be clutching, for the princely sum of $600 — a year after the detestable automatic weapons ban of 1986. That gun and my wife are the two single best investments I have ever made. If only I could go back in time and buy a dozen more. Sigh. This was obviously the ideal host for my high mileage HK416 parts kit.

The Gucciest Combat Rifle in the World

Seal Team 6 clearing room with HK 416s — In May of 2011, U.S. Navy SEALs descended out of the darkness into Abbottabad, Pakistan, to bring justice to the most reviled man on the planet. (Photo from the film Zero Dark Thirty via MovieStillsDB.com)

Using what photographs are available and a few contacts both from the military and within the gun industry I kitted out my 416 as close as I could afford to the gun O’Neill carried. That means an EOTech EXPS3 Holosight and G33 pivoting magnifier. I didn’t spray paint the thing because I will eventually want to use my transferable lower on something else.

I tacked on a superb Streamlight TLR RM2 1,000-lumen rail-mounted tactical light. This was definitely not the accessory O’Neill used, but it is rugged, affordable, and effective. The ATPIAL (Advanced Target Pointer Illuminator Aiming Laser) that the SEALs ran also likely costs more than my car.

The pistol grip on the 416 is a unique design. The bottom bit is fat while the neck is relatively thin. It feels just a little bit weird to a guy who has run an M16 for nearly four decades. There is a handy storage compartment in the bottom.

The HK buttstock is also an unusual piece of kit. The release catch is in the expected place but it is fenced to prevent inadvertent activation. You can pivot the buttplate to the side and expose space for several spare CR123 batteries. The design is a bit bulbous where it counts and produces a nice cheek weld as a result.

The forearm rail is as rugged as Chuck Norris’ jockstrap. Unlike that of a conventional M4 it is also readily removable. The front gas block tucks in nicely underneath the rail. There is no built-in provision for iron sights on my gun, but HK makes some nice ones that clamp onto the rail. With the Holosight and magnifier in place there was no room for the HK rear sight assembly.

Trigger Time

All up the HK416 is indeed delightfully compact. The gun maneuvers indoors and within a vehicle like a dream. However, it is also strikingly heavy. I’m not just being a pansy. Tricked out with the can, optics, light, and a loaded 30-round P-Mag this rig tips the scales at a whopping 12 pounds. By contrast a Colt Monitor BAR weighed 13.2 pounds.

The rugged gas piston system on the 416 has an imposing lot of mass. This makes the gun surprisingly front heavy. While that means it is incomparably controllable, it is also relatively exhausting to keep outstretched for extended periods. I suppose that’s why soldiers do all those pushups. However, killing an afternoon running drills on the range is indeed a proper workout.

HK 416 bolt disassembled next to an AR-15 Bolt — The bolt carrier assembly of the HK416 (top) differs in its details from that of the direct gas M4 shown below. (Photo Provided by Author)

The trigger is stiff but fairly typical of the genre. Double taps are fast, easy, and clean. However, on full auto the 416 is unusually spunky. I previously ran my lower on a standard direct gas upper with a 14.5-inch barrel and heavy buffer. I would estimate that the HK setup runs about 100 rpm faster on rock and roll.

Apparently this appeals to the Germans. At 800 or so rpm the MP5 always seemed a little bit agitated to my unwashed tastes as well. The subsequent HK UMP cycles at a much more sedate 600 or so rpm. No matter, nobody runs their CQB guns on full auto much anymore anyway.

Target showing accuracy of HK 416 with 4 different loads — At typical CQB ranges the HK416 is breathtakingly accurate. The gun printed these tidy little clover- leaves at 25 meters. (Photo Provided by Author)

While the HK416 and G33 magnifier will obviously reach out to 300 meters and beyond with relative ease, this really is a 25-meter firearm. The Surefire can keeps things from getting crazy given the abbreviated 11-inch barrel, but the short tube takes a serious toll on velocity. Despite the piston-driven action the suppressor will still give you a face full of hot gas as well. However, at bad breath range this really is likely the best man-portable CQB tool on the planet today.

Mechanics

Maintaining the HK416 is different from the same chore with a more conventional M4. The receivers obviously take down the same way, but the firing pin retaining mechanism is a unique proprietary design. The bolt carrier and bolt remain hugely cleaner than the same components on a direct gas gun. That was obviously the point. However, all that grunge still has to go someplace.

As part of the stripping procedure you turn out a retaining screw up front and remove the railed handguards. This screw is designed to be removed using one of the bolt locking lugs as a tool. Once the handguards are clear you can get to the gas system.

Disassembled View of HK 416 rifle parts — Disassembly and maintenance of the HK416 is similar to that of the M4 with a few notable exceptions. Field stripping includes removal of the railed forend. (Photo Provided by Author)

Like everything about the gun, the gas system of the HK416 is grossly overbuilt. The components are ample and beefy, and everything only fits one way. While protracted shooting sessions do leave a lot of trash and carbon behind, the slick finish and insightful design make maintenance a snap.

While most everything about the HK416 is absolutely top flight, I must take umbrage with the ejection port cover. This component is molded from some kind of polymer. Glock has shown us that you can make a remarkably rugged firearm using such as this, but it just seems a bit cheap on the 416.

When I took possession of my kit the gun had clearly not seen a great deal of love. I imagined the Kansas State Police SWAT guys taking their trusty old weapons out for one last fling before trading them in for something new and burning off a tractor trailer’s worth of ghastly Pakistani-surplus 5.56 to celebrate. This thing was absolutely filthy. However, twenty minutes with the same old GI-issue cleaning kit I have used since I wore the uniform a zillion years ago and some BreakFree had everything ship shape. After some proper trigger time I do love the gun.

Ruminations

The HK416 is the cumulative result of decades of mechanical evolution along with input from some of the finest shooters in the business. There are lighter solutions and countless cheaper options as well. However, I can see why the .gov guys with unlimited budgets and the entire planet as their gun store consistently choose the HK416.

By my count there are currently 27 different nations using the HK416 operationally in one capacity or another. In addition to dozens of special operations units, the HK416 has also been fielded as the standard rifle for the militaries of both France and Norway. Additionally a special variant of the 416 titled the M27 Infantry Automatic Rifle is on track to equip every rifleman in the US Marine Corps.

The HK416 is the assault rifle the M16 originally should have been. Rugged, accurate, utterly reliable, and thoroughly mean, the 416 is as good as modern technology can make it. The angry end of one of these guns was the last thing Osama bin Laden saw before facing his well-justified eternal reward. I can think of no higher accolade.