With the right optics and accessories your capability to engage threats can be greatly enhanced with an AR/M4 Carbine. In the last issue of S.W.A.T. (Part I: Setting up Your Carbine for Tactical Use), I covered the importance of a correctly adjusted butt stock, the flaws with the A2 MIL SPEC grip and proper placement of optics on the carbine. In Part II I would like focus on the forearm of the carbine with the selection and placement of foregrips, lights and lasers.
A good principle to follow when setting up accessories on the forearm is to always place everything around your support hand first. White lights and other accessories such as IR lasers should be placed where operating them is just a matter of moving one finger onto the button or pressure pad to activate.
They should not be mounted where you must adjust or change your support hand, or at least as possible. Having to re-position your hand to turn on light and lasers can possibly lead to slower reaction times under low/no light conditions. Or your support hand is interferes with your primary grip with to facilitate gripping around a light or laser, affecting your ability to effectively support and grip the carbine.
This might seem like common sense but time and again I have seen soldier’s mount IR lasers and weapon lights in poor spots on forearms of their rifles and carbines. Then they try and adapt their support hand grip around all that stuff. Whatever accessories you choose to mount on your carbine, they should be placed where they complement your method of holding and gripping the carbine, enhancing your ability to engage targets day or night.
VERTICAL AND ANGLED FOREGRIPS
Used correctly a vertical grip can complement modern methods of gripping the carbine like the C-clamp grip. (Gripping the forearm of the carbine thumb on top, with support hand fingers curled up on both the rail and against the vertical grip). This now allows you to pull straight back on the carbine, allowing you to drive the gun better from target to target and aiding in recoil control.
When mounting a vertical grip on a carbine you want to ensure you place it far enough forward on the rail allowing you to pull back on the rifle. On a normal carbine length M4 I recommend placing the vertical about two thirds up the rail towards the muzzle. You want just enough room for your thumb on top in front of the front sight post, your fingers underneath gripping the forearm with the bottom knife-edge portion of your hand resting against the vertical grip.
You do not want to mount it too close towards your magazine well. Doing this puts both your hands too close together. Like using a magazine well support, this creates an up and down pivot point. During firing the muzzle rise can be increased because of the pivot point effect, leading to slower shooting having to wait on the carbine to settle between shots.
Angled fore grips such as Magpul’s AFG are designed specifically to support a C-clamp grip. Using one puts your thumb on top of the rail and the rest of your fingers curled up around the angled grip creating a perfect C-clamp grip on the carbine. Angled foregrips I find work well with carbines that have mid-length rails and longer. With carbine length forearms there is just not enough room on the rail to mount it far enough forward to get the correct support arm extension.
The AFG needs to be mounted on the forearm where you can extend your support arm out about 75-80% of the way, elbow resting naturally down. Arm too straight can place too much muscle tension on your support hand wrist, and muscle tension leads to muscle fatigue that can affect shooting. The key, like a vertical grip, is that an angled foregrip should be positioned to allow you pull to straight back on the grip, aiding in settling recoil and helping you drive the gun.
In deciding on to use a vertical or angle foregrip, it depends on the overall use of the carbine. Is it just a range plinker or competition set-up for something like 3-gun. I recommend basing your decision solely on whichever one seems to balance the carbine the best and facilitates your natural arm extension and grip.
For a tactical or defensive carbine foregrip selection is a little more difficult. In addition to holding the carbine and controlling recoil, your support hand needs to be able to effortlessly operate the controls of the lights and lasers required on a fighting carbine.
CHOOSING THE RIGHT LIGHT
The first weapon light I ever used that attached directly to a rail was the Visible Light Illuminator (VLI), from the first SOPMOD issue back in the late 1990s. Powered by six AA batteries, you could activate it via toggle lever or a pressure pad and it’s incandescent bulb produced a whopping output (for the time) of 90-110 lumens. (Having used one first hand, I would say the output was definitely closer to 90 Lumens).
Thankfully weapon lights have evolved since then, to now most where weapon lights start around 200 lumens and you can choose anything from lights with several brightness settings to lights that also include IR and strobe functions.
With all the various weapon lights out there choosing the right want can be a process. Just how bright of weapon light do you need and what functions for a tactical set up?
Starting with brightness level, a weapon light needs to be able to at least brightly illuminate out to a distance of at least 50 yards or so. Lumen wise really any light with an output around 150 will get the job done. In CQB that is enough output to illuminate most rooms and long hallways you might come across.
As far as using a weapon light with multiple operational modes such as; strobe, IR etc. I think it should depend on the purpose of tactical carbine. For purely a self-defense where your illumination needs might simply be to be able search and clear your home in the dark the KISS (keep it simple stupid) principle might apply. A simple one setting white light might be all you need.
A light with multiple buttons or one that requires a certain amount of presses on a button for the beam or brightness you want just might be too complicated. Under the pressure facing a real threat the last thing you want to do is to be fumbling around with the controls on your weapon light when you should be scanning and looking for threats. A single setting light controlled via a simple pressure pad makes perfect sense for many looking for a hom- defense set up.
Now for tactical operations where you are not only shooting in self-defense, but are expected to go on the offensive such as room clearing and CQB, having a light capable of multiple modes can come in handy. Strobe functions, multi-brightness settings and being IR capable (applied correctly) can come in very handy for tactical work.
A strobe setting (very fast pulses of light) can be very disorientating to the person viewing it. Aside from making yourself hard to spot due to the strobing light, it becomes very confusing and hard for the enemy to pin point where and how many assaulters there are if the whole team is all running strobe lights.
The benefit here is if you can cause some confusion with strobing lights, you are slowing down the enemies ability to process information. Anytime you can affect some ones reaction time you have an advantage in a combat situation.
Moving on to multiple brightness settings on a light, they can be useful if you want to check something out under white light, but do not want to use a super bright beam. One thing to keep in mind with white light in CQB, every time you turn it on to engage a target—even from inside a structure—you chance pinpointing your position to outsiders looking in via windows and openings. So having the capability to dim down during soft searches or re-clears can minimize this danger.
Lastly, if you have IR capability with your weapon light that gives you the ability to illuminate an area much the same as an IR flood beam setting found on most IR lasers. If you can make do without a IR laser pointer for aiming an IR capable light makes for a cheaper alternative to purchasing a separate IR laser such as the LA-5. If anything it gives you a backup or suppliant to your IR capability while running blacked out.
WEAPON LIGHT MOUNTING OPTIONS
While picking a light with the right operational modes and brightness output is important, another factor to consider when choosing a weapon light is its method of activation. Depending on how the light is activated it can determine the light’s mounting options.
I prefer lights with a pressure pad mounting the light on the the opposite the side of my support hand, with the pressure pad on top of the rail. Doing so will allows a modern style C-clamp grip and with the thumb naturally resting on top it is right on the pressure pad. One thing to keep in mind though with this set up it is very easy to white light AD, as you can activate the pressure pad just by the natural tension of your hand from gripping the rifle, either from shooting or just carrying the rifle.
While I usually stay away from mounting lights on the same side as my support hand the one exception is with the Inforce WML (Weapon Mounted Light). Because of its angled push button it fits perfectly right in front of your support hand on the same side. Moving your thumb from the top rail to the side, pointing it towards the target, puts it right on the angled button with very little sacrifice of support hand grip. From here it is very easy to manipulate the button and control on the WML.
In addition to same side support hand mounted the WML also works great mounted at the 12 o clock on the forearm. Again with its angled button it can easily accessed by your support hand thumb as it rest naturally on top of the rail.
While I am not personally not a fan of top mounted lights (running a top IR laser it is not practical on my combat set up rifle) it can be a good option for many who only do run a light on their rifle.
Twelve o’clock mounting works especially well with lights that use toggle style buttons found such as those found on most pistol style lights like SureFire’s X300 and Streamlights TRL series. Again using a C-clamp grip, they are very easy to operate with your support hand thumb.
One more light activation method that effects where it is best mounted on a carbine are push button tail cap lights. If you are using a straight vertical grip a push button tail cap light makes a great choice. Mounting it to where the push button tail cap is within reach of your thumb after you wrap it around the vertical grip. If I am running a white light with an IR laser this is one of my preferred set ups. I always run a pressure pad switch for my IR laser taped to the side of the vertical grip.
Using a pressure pad tail cap light/vertical grip combo with an IR pressure pad, both controls are in the same position for my support hand. With no need to adjust my support hand around between controls, switching between the two is instinctive and more importantly I can do it very quickly. Although in order to operate the light or IR laser I must switch from a C-clamp grip to holding onto the vertical grip it works well for the way I employ a light and IR laser.
Without going into TTP’s that much, the only time I use a white light is indoors and my expected engagement distances are CQB. At short ranges (room distance) not using a perfect C-clamp grip does not hinder my ability to shoot fast and as accurately. And using an IR laser with NOD’s because you are looking over the rifle aiming with the laser (usually a center chest style hold), a perfect C-clamp is not required.
ADDITIONAL MOUNTING CONSIDERATONS
The main reason I always prefer to mount the weapon light opposite of my support hand, I do not want to be gripping around an object to hold onto the carbine. A wide grip on the forearm is not as strong as a narrower grip, hence that is why you see smaller diameter rails being used more by top 3-gun competitors. Using a smaller grip around the forearm allows for better control of the rifle which can equal faster split times between shots and faster target indexing.
Same side, top or bottom mounting of lights is fine as long as they are not in the way of your support hand.
One more additional consideration to take into account regardless what clock direction the light is mounted on is not mounting is so far forward where the bezel of the light is near the muzzle. While most weapon lights have some sort of shock rating and are designed for the muzzle blast and recoil of a weapon, placing it right next to the muzzle adds extra stress to the bulb possible degrading its operational life.
Additionally having your light mounted parallel with your muzzle exposes it to possible extra impacts. Aside from the obvious muzzle striking of an opponent, your muzzle can come in handy for other tasks such as window clearing.
A good technique in CQB for window breaching—after you break or blow open the building or car window and prior to going through or reaching in—you rake the muzzle of your M4 across the window sill breaking off any jagged pieces of glass that might catch on you or cut. Doing so with a light mounted next to your muzzle cannot be a good thing if you are expecting a long service life from that light.
MOUNTING IR LASERS
In regards to mounting IR lasers, typically you see most shooters mount theirs as far forward on the forearm as possible. This is done so that there won’t be any IR splash off the front sight post or blocking of the IR aiming laser or IR flood beam. I actually find this reason to be flawed, maybe with older models of lasers such as the PEQ-2, which had a weaker beam there was a chance of front sight interruption.
With the newer generation of IR lasers such as the LA-5 and LA-15 there is little interruption with the front sight. However, mounting the laser forward you are forced to expand your grip around the laser. As mentioned with weapon lights, this can mean a less comfortable grip and possibly a weaker grip.
My recommendation is to actually run the laser behind your support hand just in front of whatever optic you are running. Doing so allows a C-clamp grip on the rifle and despite what many believe, being mounted a few inches back on the rail there is no interruption or blockage by a fixed front sight of the IR aiming laser. The only interruption that might occur is if you have an IR flood beam you might notice a little shadowing from the front sight.
Now there are some that do prefer to use the built in push button on the top of the LA-5 and 15’s and do not mind a wider grip. In this case it is preferred to have the laser mounted forward on the forearm so there thumb naturally rests on it, making it very easy to activate the IR laser with the support hand thumb.
There is always the option of side mounting a laser. Although it’s an option I don’t recommend it. Using an IR laser you are already going to have some side and height above bore offset. Side mounting the laser complicates things by making the offset even more. In CQB engaging targets at room distance requires split second processing of information. You already have to factor in one hold off for whatever primary optic you are running. With a side mounted laser depending on what side it’s mounted on, the laser beam could be down low or really high. Either way it will require you to remember two different holds—one for your optic and one for your laser.
Staying with a top mounted laser—aside from a little side hold off, maybe an inch or so—your hold off almost exactly matches that of your optic. Under the pressure of a firefight whether you are using your optic or IR laser you do not have to change your hold off that much. Because of this I always recommend top mounting the IR laser. The less I have to remember in dot placements and hold offs the better.
THE WRAP UP
One of the reasons for the popularity of the AR/M4 carbine is it’s easy to customize and accessorize based on the shooters needs. Whatever the expected situation—CQB, long range shooting, day and night operations—along with proper selection of accessories the proper placement of the accessories themselves is paramount to you being able to shoot at your best.
To shoot your best always build upon your method of holding the rifle. In doing so you set yourself up with the best chance of winning the fight.
Jeff Gurwitch has 23 years of military experience, the past 16 with U.S. Army Special Forces. He served in the first Gulf War, three tours OIF, and two tours OEF. He has also been competing in USPSA, IDPA, and 3-Gun for over a dozen years.