Building an Airsoft U.S. Infantry M4 Clone

Airsoft Guns & Builds

In a sea of Keymod and MLOK, why not do something different?

For this build I decided I wanted to replicate the rifle a U.S. infantryman would be using. I’ve always been a sucker for M4s with the original Knight’s Armament Co. quad rails, and the build still has a lot of the features you’d see on more “high speed” rifles.

This rifle is going to be paired with an impression based on 10th Mountain Division troops from 2012-2014. This was the period where the Army switched from UCP to Multicam/OCP pattern uniforms and equipment. During the transition it was very common to see a mix of the two patterns, and the kit is extremely ugly a nice change of pace from the chest rig RECCE and Russian loadouts I normally do. Because of this, there are certain attachments on the gun that were not common across the entire Army, which I will point out.

This article is a companion to a video I did on this rifle build. If you’d like to watch the video, you can check it out here:

The Base: Elite Force/VFC SOPMOD M4

This is one of the newer offerings from Elite Force and VFC, and I couldn’t be happier. Seriously, it’s my new favorite airsoft gun. VFC combined their Avalon internals with the old school looks of the M4a1 which is something we don’t see too often. Ever since Keymod and MLOK became the cool new thing we’ve seen a transition away from rifles with traditional RIS handguards. I’m really glad VFC offers this out of the box so I didn’t need to find a real version of the rail, which can go for $150 or more.

This is the base for any infantry kit in this timeframe. Besides the KAC railed handguard discussed above, this rifle features a 14.5″ barrel, Triangle front sight post , and other clone correct furniture like an A2 pistol grip and SOPMOD style stock. The rifle has an orange tip styled after the KAC NT4 flash hider, but I would suggest switching it out for a standard birdcage flash hider to be clone correct.

One of my favorite features of this rifle is that the barrel is a two piece design. The barrel is 10.5″ long (with a 300mm inner barrel) and has a 4″ extension glued onto it to give it the standard infantry look. This allows you to turn the rifle into a CQBR style rifle if that’s the look you’re going for. It’s not correct for the impression, but I love the option to have a Block 1 style rifle for other kits or indoor play.

Attachments: Optics and Iron Sights

There are a few types of optics that are appropriate for this kit, which allows you to put your own spin on the rifle without being farb. The first is the Aimpoint M68 CCO. This was one of the first optics I owned for airsoft, so maybe it has a special place in my heart. Maybe it’s just cool looking, who knows. There’s tons of replicas available, mine is from Lancer Tactical but G&P also has a really solid offering as well. If you’re not a fan of Aimpoints, EoTech 552 (AA version) sights are also correct.

If you’d like to have some extra range there are magnified options like the ACOG. From my understanding 10th MTN used the normal ACOG and the models that accept RMR/Doctor red dots on top, but the ones with iron sights on top are not correct. If you’d like to really go crazy the Leopold Mark 4 scope has been seen in use as well.

It’s also important to talk about back up sighting systems. The triangle front sight post is non negotiable. Rear iron sights for this kit include the MA-Tech folding sight, which can get pretty expensive. A&K offers a replica (called the Masada rear sight) but I’ve heard varied reports of the QC on them.

The MA-Tech rear sight is more of a 10th MTN. piece of kit compared to what the entire infantry was using. If you can’t find one of these rear sights the Knights Armament 600M flip up sights wouldn’t look horribly out of place on this rifle. Detachable carry handles are also correct, but why would you do that to yourself?

Lasers and Lights

Acceptable lasers include the PEQ-15, PEQ-15A, Steiner DBAL A2/I2 or the PEQ-2, which is an older unit but still saw usage during this timeframe. This is one of the few times you can add some color to the rifle besides black, because tan PEQ boxes were common.

Depending on what you’re looking for out of an PEQ box, you’ve got a lot of options. You can get a dummy box meant to hold batteries, but these tend to be cheaper and don’t look as nice. I personally use the Bravo PEQ-15 replica, which is IR capable out of the box and doesn’t break the bank. Check out my review here:

Not everyone was issued a flashlight, but if you were you probably got a Surefire M952. These can be found cheaper than most SF flashlights, and replica companies like Night Evolution offer copies if you’re on a budget. This is one part of the build I have not gotten yet, but my plan is to have the PEQ box on the top rail, with the Surefire on the right side and my foregrip on the bottom.

Foregrips & Pistol Grips

The foregrip I chose for my rifle is the Knight’s Armament Co. Foregrip. They came with the rail system so it was very commonly used across the Army. they were also used in the SOPMOD program for Special Forces as well. Because this is something that is easy to remove, it’s common to see some variety in what was used. Magpul RVGs were common, and troops also used the GripPod to avoid having the extra weight of a full bipod on their rifle. If you’re going to buy one of these, get a real one. I’ve had a couple of replicas break because the legs are always made from really cheap plastic.

Pistol grips are pretty simple: black A1 or A2 grips only. The VFC SOPMOD M4 comes with an A2 grip installed, and they’re very common across the airsoft industry. If you’re like me and hate the finger nub on the grip shave it down with a Dremel and sandpaper.

Stocks & Slings

Another area where you have some choice is the rifle’s stock. There are three main types that were seen in use. The classic “LE” style stock was the most common, while old school CAR-15 (metal or plastic options) were still being used as well. SOPMOD style stocks were also commonly used, and the VFC SOPMOD M4 comes with one out of the box. I like it because they have much more battery space than the other two opinions, but buffer tube lipo batteries are extremely common now if you’d like to do one of the other two options.

Slings are a tricky part of the kit because some people were issues slings, while some were private purchase. The VTAC 2 point sling was commonly used and is my favorite sling I’ve ever owned. You can get away with pretty much any two point sling as long as it’s in tan or black.

The Finishing Touches

Sometimes it’s the small details that make the biggest difference. A common practice was to tie down your attachments to the rifle using paracord. Infantry rifles go through a lot of hard use, and it’s not unlikely someone could lose their PEQ box or optic out in the field.

There’s other things you can add to the rifle to make it your own, such as armory numbers on attachments (again, for accountability) and the rifle itself. Small details such as using USGI style metal magazines will also look nice in the rifle and give it that “standard issue” feel to it.

I’m building this rifle to serve as a rifleman at milsim events, but other roles would call for different attachments on the rifle. M203s and HK M320s were also used with M4 rifles, and other specialized roles used weapons such as the M249, M110 or EBR during this time frame. There’s lots of variety in this kit despite being infantry where everyone supposedly gets the same equipment, and you can really make this kit unique without standing out.

Want To Learn More? Check Out T.F. Keg!

Task Force Keg is a impression group focusing on the 2012-2014 10th Mountain Division kit mentioned earlier in the article. They’ve been a huge help when I was researching for this build, and I plan on building my impression to their standards. If you’re looking for an impression team that goes to events like Milsim West, make sure to check them out. I love seeing more infantry units in games like these, because it’s much more realistic than NATO SF fighting Spetsnaz all the time. If you want to learn more, I highly encourage you to watch this video from Gun Gamers some of the members put together.

Lane

Lane is the head of Content Creation and founded The BB Warrior in 2014. When he's not playing airsoft Lane is working on a degree in Broadcasting, or playing Fallout: New Vegas for the 100th time.