WMLs | Considerations for Lights, Mounts and Features

What are the considerations for a weapon mounted light? Mounting, certainly. Activation process, sure. Brightness? Maybe, maybe not. As you may recall, Mad Duo David put something on Facebook a while back about needing a WML (weapon mounted light) and asking the various features thereof (including whether or not there was a need for constant-on). Dave Merrill responded with a quote that included, “…the objective has been taken; have everyone turn ON their damn lights to constant ON. Why? Well, first and foremost the lighting conditions in places where you kick-doors-and-shoot-people-in-the-fucking-face aren’t always consistent. After the objective is sealed, turn the goddamn lights on…” We asked him for his perspective about the matter. Here it is. (If you want a a recap of the conversation that led to this, let us know in the comments.)

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A weapon mounted light (WML), for both rifles and pistols, is a critical item for both defensive and offensive shooting situations. This article is mostly concerning rifle lights but there will be some mention of pistols. I started out this piece with a lot of lists and features but it was pretty dry. So instead, I’m basically going to rant for a few minutes about WMLs.

A WML, by definition, has to be mounted. The light should be mounted as far on the forend as possible while still allowing for quick and precise control by the shooter. What forend someone is rocking often determines what light and mount setup is used.

WMLs | Considerations for Lights, Mounts and Features
WMLs | Considerations for Lights, Mounts and Features



If you have a rifle equipped with an A-frame FSB the forend itself doesn’t matter. One setup that I used for many years is a Midwest Industries FSB rail mount + Vltor light mount + Surefire 6P. This puts the light in a position which was both easy to activate and hard to inadvertently employ; right around 11 o’clock for a right-handed shooter.

WMLs | Considerations for Lights, Mounts and Features
WMLs | Considerations for Lights, Mounts and Features

Now, this isn’t a perfect setup. If you have to shoot from the support shoulder the light can be hard or even impossible to use (and your hand may obscure some of the sight picture) depending on the diameter of the forend and the size of your hand.

Some people actually like to mount the light on the, ‘wrong’ side just so it’s even harder to willfully enlist and therefore help mitigate the risk of a white light ND (there are other considerations for, ‘wrong side’ mounting as well but that’s a discussion for another time). Me? I have small hands with the accompanying flanges so even with a skinny forend like a Noveske NSR I can’t really do it easily or comfortably.


If you don’t have an FSB, no sweat. There are several other options out there that can put that light right at the 11 o’clock/1 o’clock sweet spot. The Impact Weapons Components (IWC) Mount-N-Slot series has mounts for lots of popular forends and lights. The offset and forward IWC mounts (such as the Haley Strategic Partners Adaptive light mount) work great for extra hand space even on the short (errr… original?) 7” carbine rails and forends. Without an offset and forward mount for the light on a 7” forend, the hand isn’t left with a lot of places to go.

If one has a longer rail or forend you have even more options. If you have ape arms, yes indeed you can still use a forward mounted light with a 13”+ rail comfortably. If you’re like the rest of us you can use an offset mount + light.

An offset mount can either be placed on the 12 o’clock rail with the light oriented either to the left or the right or on the3/9 o’clock rail (assuming a quad rail) with the light oriented towards the top. There are a few other setups that can be done if you’re utilizing a VFG in full-fisted banana-grabbing mode; these setups are currently not en vogue for a reason but it can still be done.

If the light is right next to the muzzle of the rifle (like say and FSB mount on an SBR) don’t worry about it so long as you’re running a quality light. Yes, the glass will get gummed up but that’s an easy fix (to be addressed later on in this article).


Another way to mount a light is the Rhino configuration. This is usually done with pistol lights (it’s called, ‘Rhino configuration’ because it makes the end of your rifle look like a rhinocerosaurus!). The light is mounted upside down and in front of either an A-frame (if utilizing a rail with an FSB cutout such as the Daniel Defense 12” FSP rail) or front sight (such as a fixed DD front sight mounted on a rail, as shown below).

WMLs | Considerations for Lights, Mounts and Features
WMLs | Considerations for Lights, Mounts and Features

The Rhino is the only way I’ve seen a pistol light mounted on a rifle that is simple to use, out of the way, and not prone to white light NDs (especially when slung and hands-free).

One of the advantages of the Rhino is that it’s completely ambidextrous. Regardless of what shoulder the rifle is mounted on, activation is the same. A Surefire X300 is my favored light for this setup. Though a TLR-series can also be used in this manner, I prefer the soft-push for momentary on as opposed to the rocker switch. Why?–because from either side, the X300 is a soft push-for-momentary and a rocker for constant. With the TLR in a Rhino, the left side is push-down-momentary and push-up-constant. To make matters worse it’s the reverse on the right side.

Some quick notes on mounts themselves:

Just like with hand stops and VFGs, a less robust option isn’t always a bad thing. The hell you say? Yes, I’d rather the light mount get broken off rather than hang me up too long in a doorway during a live shoot or mangle the hell out of my rail during training. Here’s a picture of a VTAC light mount I broke on a door frame:

WMLs | Considerations for Lights, Mounts and Features
WMLs | Considerations for Lights, Mounts and Features

However, the important part is that it broke off instead of hanging me up. Had I been running my Vltor QD offset? Dunno. I still have tough metal mounts with rigid locking systems around, just something to keep in mind. It is noteworthy that the more low-pro your setup is, the less likely you are to run into the problem of getting the light snagged on stuff.

Speaking of QD…. Why do they exist in the first place? Do I really need a LaRue locking lever for a light? I could see it if I had only a couple of WMLs and three times as many rifles but I set up every rifle as its own individual self-sustaining island. I recommend others do so as well (provided the time, money, and opportunity to do so). That means no sharing of slings, optics, lights etc between rifles.

Though I said you can go cheap, I didn’t mean go Simplэ Jack.

Build that blaster on a budget.

AR 15 budget blaster bits at Brownells.
Click for current sales and specials at Brownells.

You can widely ignore people that advocate simply putting a plastic rail on a carbine handguard and attaching a scope ring; scope rings are not light mounts. Scope rings are meant to hold relatively fragile metal tubes with glass in them on top of a rifle—not to be knocked around. Vltor light mounts don’t cost that much (~$35) and don’t shake apart with repeated use like a cheap scope ring; robust scope rings will cost as much, if not more, than a Vltor light mount.

If your light mount uses a thumb screw or torx/hex, use blue loctite and witness mark them with a paint pen. Inspect the mount as you would any other part of your rifle during PMCS.


By far, my favored activation method is a soft-push momentary rear switch. No clumsy clicky-clicky or slow and awkward twist garbage or rockers that need to be veered in different directions depending on how it’s being used.

Just. Dead. Simple.

I’ll go on record by saying that I don’t like pressure tape. Many of them are finicky and white light NDs can be rampant (if you have to use a pressure tape, only use a modern Surefire one and please please do not mount it someplace where it’s easy to employ unintentionally or without deliberation). 12 o’clock pressure tape would be my preference if I were forced to go that route due to equipment requirements.


Regardless of your rifle light setup, if you have had some problems with white light NDs, your light doesn’t have a kill-switch and cannot change lights/mounts (be it that you are not allowed due to departmental regulations or otherwise) I’d suggest getting a kill/beam cover. Surefire and other flashlight manufacturers sell them and they are relatively inexpensive. Before you go into a house, flip the cover back. It’s a fairly simple solution that doesn’t involve a lot of twisting/working. One of the ways I’ve seen some others accomplish this is by untwisting endcaps/bezels enough so that the contacts don’t touch. I recommend against this practice for this reason:

-If you twist either end of the flashlight enough to lose electrical contact, it means it’s loose. That means you risk the flashlight coming apart from simple vibratory movement (such as riding in a car). It also means you don’t have a good environmental seal and foreign debris can get in there and muck everything up.

In short: Get a light with a kill switch or get a kill cover if the light can be activated unintentionally.


I want two (well, three) settings on a WML:

-Passive off (don’t do anything and it stays off)



The usefulness of momentary-on should be readily apparent. If it is not, I suggest getting some quality low-light training.

A constant-on, while an incredibly stupid and misguided idea for active engagement, can have a place after the fight.

Some people have railed and rallied against having a constant-on function at all. I do not agree with them. A constant-on, while an incredibly stupid and misguided idea for active engagement, can have a place after the fight. IE: Objective is secured and it’s one-site-exploitation/investigation time. You can never count on the power being on (either due to third world grid, [lack of] infrastructure or from power being deliberately cut prior) post-raid.

Sometimes you want every flashlight on that you can find. The spill and splash from a dozen turned-on weapon lights greatly boosts available light. The constant-on function is also useful for the cover man/guard during the search/restrain phase of detainee operations.

Back before LED’s, this meant a lot of battery changing (and battery changing should be done on a consistent basis even with LED bulbs) but it’s nowhere near as bad as the, ‘holy shit my light only runs for 20 minutes before dying!’ days.

Lights that can cycle through 15 different lumen-levels and send SOS signals and order a pizza are good–for a light that rides in your pocket or belt. WMLs should basically be: Zero to High. No two soft pushes for high and one for low etc etc etc. You shouldn’t be using your WML to read a map. Keep the multifunction lights for finding your dropped keys in a parking lot.

What about a strobe function? Strobes have a place. That place is photography, attempting to get VD at a dance club, or some combination thereof.

What about a strobe function? Strobes have a place. That place is photography, attempting to get VD at a dance club or some combination thereof.


Firstly, no; more is not always better. There has been a trend in the industry of constantly upping the ante regarding the lumen levels of flashlights, be they WMLs, pocket lights, headlamps, or otherwise. Flashlight geeks the world over seem to be on a perpetual prowl for the blazing brilliance of a 5k lumen light. Such a light will make even the hardest criminals quiver in a cascade of blindness! I mean, what could go wrong, right?

Several things, actually.

Have a gander around your house. Do you live in a place with no reflective surfaces? No white walls, white or stainless appliances, windows, mirrors, televisions, picture frames, computer monitors or anything reflective? My guess is that no, you do not live in such a place; most people don’t live in matte shoot houses. You don’t want to get the shit needlessly blinded out of you when going through a structure. There are methods for preventing this–but if you’re in a group, just expect to get dazzled. And learn to deal with it.

As an aside, one of the ways we prevent the overuse of WMLs during low-light training is by hanging a lot of mirrors—people learn really fast that way.

Besides gratuitous self-hindering, a WML with a too-high lumen level can actually wash out your RDS when inside a structure. I’ve seen this happen even when the RDS is turned up to 11 (and consequently blooming like crazy).  WMLs with a very large hot spot can do the same.

No matter how bright your light is, one cannot run on the assumption that their light alone is going to confuse or disorient someone targeted.

Many other factors other than lumens can contribute to exactly how usable a light is (reflector type, light dispersion etc).

I like a light with a lot of dispersion/spill with a bit of a hot spot for checking deep structures/corners; not a super-focused beam. If the beam is too focused, the hot spot can wash out target details (just like it can do with a RDS) and also cause the shooter to pay too much attention to the spot itself. Those that advocate using a WML outdoors (I do not in most circumstances) may need lights with more throw to meet engagement parameters.


Before you go out and cut acetate, rub special oils/lotions or other such nonsense on a light to prevent powder fouling just grab an eraser. The light pictured below spent a lot of time right next to the muzzle of an SBR. Look how quickly it cleans up:


WMLs | Considerations for Lights, Mounts and Features
WMLs | Considerations for Lights, Mounts and Features
WMLs | Considerations for Lights, Mounts and Features
WMLs | Considerations for Lights, Mounts and Features


Far too many people just stick a WML on their rifle with no idea of how/when/why to actually employ it. No matter what setup you decide to go with–go out and actually train for low-light encounters.

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Emeritus Dave Merrill wrote for Breach-Bang-Clear from late 2013 until early 2017, including a year as its Managing Editor. He departed our ranks in May of 2017 to accept a well-deserved position as social media manager for RECOIL Magazine. He is a combat veteran of the Marine Corps who describes himself as a "...former urban warfare and foreign weapons instructor for Coalition fighting men." Merrill's articles are well worth the time it takes to read them - there's a lot of knowledge tucked away in that skull.

DFM has 78 posts and counting. See all posts by DFM

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