Retro builds: M16
Our take on cloning the famed infantry service weapon
The prevailing trend of cloning current and past military firearms is still going strong. While some simply wish to duplicate a rifle that they were once issued while in the service, other enthusiasts are on a mission to clone them for their own personal collections. With so many rifle clone build options around, it’s hard to choose which project to tackle.
In recent issues of World of Firepower we’ve assembled two clones and we’re going for our third in the series in this issue. If you’ve missed out on the previous issues, locate our back issues to see how our Mk12 and M4 clones turned out. In this installment, we tackle the wide, and deep, world of the M16. As America’s frontline combat rifle for the past 50-plus years, the M16 is not only iconic, but still serves as one of the workhorses of today’s military. Versions of it first saw combat in the jungles of Vietnam and are currently employed in the War on Terror throughout the globe. Regardless of how accurate you want your clone to be, the many versions of the M16 that exist can make taking on such a clone project an overwhelming proposition.
Where shall we begin? We’ll start off by say- ing this article is not meant to be a primer on the quintessential M16 build. For that, you’ll probably need a telephone-book-thick guide and a Master’s degree in M16 history. If you want to get into the smallest details and include long out-of-production parts on your build, don’t let us stop you. By all means, read up on the subject and hunt for all the vintage parts you’d like.
For the purposes of this article, we will assemble an M16 clone with off-the-shelf parts that are currently widely available. Perhaps you might even already have what you need to start your build lying around in a spare parts bin.
We began our build by first deciding which model M16 we wanted to replicate. With so much history, this is an important decision to make before ordering a single part. We decided to go with the earlier M16A1 variation. The M16A1 saw extensive use in Vietman and was the standard service rifle for the U.S. military well into the mid-’80s.
The M16A1 can be visually identified by its triangular handguards, buttstock without the cleaning kit storage compartment, a threepronged flash suppressor and select fire capability. Our clone will duplicate the above minus the full-auto fire feature.
To save a few bucks, we based our build on a Brownells M16A1 BRN-16A1 blemished receiver. These are called cosmetically blemished by Brownells because the Safe and Fire markings are engraved on both sides while the original only had them on one. For buffs of detail and authenticity, the BRN-16A1 helps duplicate an often-overlooked detail that many M16A1 clones miss: It features the proper M16A1 front takedown lug profile and profile surrounding the receiver extension. Almost all forged lower receivers currently produced feature the A2 takedown profile, which is incorrect for M16A1 clone builds.
We mated the lower to a Brownells M16A1 upper receiver. Like the lower, the upper is made
“To complete the look, we installed a retro furniture set.”
by Brownells in conjunction with
Nodak Spud to match the features of the original M16A1 receiver. Made to replicate the M16A1, this upper duplicates the original’s profile perfectly. As with the original, the reproduction is made with no shell deflector and its A1 rear sight housing and carry handle feature proper contours.
A quality preproduction barrel was installed in our upper assembly. The Brownells Retro A1 rifle-length barrel assembly is chambered in 5.56x45mm NATO, is chrome-lined, and has a 1/12 twist. The 4150 chrome-moly steel 20-inch barrel is finished in black phosphate and is magnetic particle tested.
Other final details added to complete the upper include a 3-prong A1-style flash hider as well as an A1 rear sight assembly, both made by Luth-ar. We also installed a teardrop-style forward assist made by DPMS as these style assists were used on the original M16A1S.
Completing the Look
To complete the look, we installed a retro furniture set, also made by Brownells. The M16A1 style buttstock, handguard and pistol grip are modeled off of original components, so authenticity is almost spot-on. We say almost because Brownells changes some areas due to modern manufacturing methods or to help avoid counterfeiting concerns. The furniture sets are available in different colors for those looking to build faithful reproductions of rare variants. We chose black since it is proper for our M16A1 clone.
We didn’t go overboard with the details of this build and just kept it simple. If you wish to sink deeper into it, there are plenty of small details that you can delve into. We completed our A1 build with a modern bolt carrier group (BCG) and charging handle by Brownells. The M16 profile BCG is black nitride treated for reliably smooth operation and easy cleaning.
A part of the fun of the AR-15 platform, other than shooting it of course, is to outfit it in different ways. Now that we had our A1 configuration completed, we looked into what it would take to form our rifle into other M16 variants.
“the M16’s many versions can make taking the project an overwhelming proposition.”
From our research, the M16A2, which was developed at the request of the U.S. Marine Corps from combat experience gained in Vietnam, uses a slightly different upper receiver that features a new rear sight and brass deflector, round-style handguards. It also has an updated pistol grip, flash hider, forward assist and a buttstock that has a storage compartment for a cleaning kit. A2-style parts are quite common even today. We imagine you probably have a few of these parts already.
Those with super-sharp observation skills will also notice that the front sight base and lower receiver’s takedown area are also contoured differently. We obtained many of the parts to reconfigure our A1 build to A2 from Del-ton. A proper A2 build will also switch out the barrel. The A2’s profile and twist rate are different, with the rate going from the A1’s 1/12 to 1/7. The real M16A2 also switched its alternate firing mode to burst, from the A1’s full-auto, but that doesn’t affect our semi-auto-only clone build.
The M16A3 is a slightly modified version of the M16A2 that was used by the U.S. Navy SEALS and other units. The main difference being that it featured the M16A1’S full-auto mode trigger group instead of the A2’s burst firing mode. For the purposes of clone building, the A2 can stand in for the A3. If you’re going for an even more authentic look, perhaps the firing mode can be laser etched to match the original’s markings.
Today’s military-issued M16 is the M16A4. The most notable difference of the A4 is its fully railed flat-top upper receiver with detachable carry handle as well as its railed handguard. We obtained an upper from BCM and fitted it with a Knights Armament Company (KAC) M5 Rifle RAS Forend Assembly. The KAC M5 is the same rail that is issued to the real M16A4 and is perfect for a clone build.
We set out to build a simple M16A1 clone and were able to do it relatively easily thanks to the many companies that are now supporting the retro build movement. We made a conscious effort to avoid going into the never-ending road of minutely detailed variations and came out unscathed. If you want to take your build to another level, there are resources online that can take your clone build there.
Armed with components to cobble together A2, A3 and A4 variants, we’re now tempted to build out three more M16 clones. As a gun fan—especially an AR fan—you may know how it is. But with so many projects to get going, we’re already conjuring up our next clone build.
“you might have what you need to start your build in a spare parts bin.”
The M16 is not only iconic, but still serves as one of the workhorses of our military today.
01. Both the M16A1 upper and lower receivers offered by Brownells are made of Nodak Spud forgings and machined by Brownells to exacting detail. 02. As seen here, the M16A1 uses a teardrop shaped forward assist, an upper without a shell deflector and a lower that is contoured differently from more common A2 version lower receivers. 03. Eagle-eyed enthusiasts will notice that the A1’s front sight base is contoured differently from the ones found on later models.
04. The M16A1’S carry handle incorporates an early version of the M16’s rear sight. 05. If you want to go with a more modern clone, BCM makes a complete M16A4 upper receiver group that is ready to slap on your lower.
06. A flat top receiver and detachable carry handle can be found on modern M16A4 models.
To begin our build, we used a Brownells M16A1 BRN-16A1 lower and a Brownells M16A1 upper.
There’s nothing quite as satisfying as sourcing and assembling a clone build piece by piece.