Product Review: Leupold MX 431
The MX-431 is part of Leupold’s MX Modular Flashlight System, which consists of interchangeable bezels, main tubes and a tail switch
I tested the Leupold MX 431, a tactical flashlight offering by Leupold. My test proved that Leupold makes torches the same way they make quality tactical scopes. If you believe your tactical light should be built like your chronograph, this light is for you.
The MX-431 is part of Leupold’s MX Modular Flashlight System, which consists of interchangeable bezels, main tubes and a tail switch. The system was designed to give the user configuration options based on the mission. Each modular part is of machined aluminum, milled with the same type of precision as their riflescopes.
The MX-431 has a strobing option, which can momentarily distract a suspect or disrupt their current pattern of behavior. Strobing is a rather innocuous force option with many advantages. For example, it allows an officer to mask movement.
The MX 431 version is the tactical model with a three-cell (CR-123a) maintube, multifunction tail switch and the MX-400 Multi-Mode LED Tactical Bezel. This model fires a 175 lumen steady beam, a blazing strobe with the same intensity, a 10 lumen worklight and a 25 lumen SOS signal. This torch has some unusual appointments, including a sapphire lens.
I’m a firearms guy. I went through about a half dozen torches in my law enforcement career, which is why I got into testing equipment. When I test a torch, the first thing I like to do is shoot with it.
Before reading the instructions, I dropped in some CR-123 cells and headed for my local range at dusk. After a few boxes of 9mm the lens was dirty. I wiped it clean with a rag and kept shooting. When using techniques which apply fingertip to bezel, one can take advantage of the heft for controlling recoil.
The MX-431 is a little heavier than similar products, the same way a Lamborghini door feels like it has more substance than the family sedan. This is also probably the most precision machined light on the market. It has the kind of checkering found on a handgun and nearly flawless flats and textures, which aid in tactile alignment and gross motor manipulation. They have even threaded the front of the bezel, just in case one needs to screw on some filters.
The Leupold MX 431 has a sapphire lens, a material that is many times harder, more durable and transparent than glass. This material is hard enough to resist a scratch from a pocketknife or the abrasive discharge of gases from my muzzle. This is kind of over-engineering for a tactical torch. Having said that, I have some torches I no longer use because of cloudy or broken lenses. Sapphire won’t bulge when the light is left on long enough to melt a piece of plastic.
The MX 431 has a deep parabola reflector. It throws a very bright center with a rather gradual spillbeam. It has more of a floodlight quality than a searchlight beam, which means it is great for building searches, where an entire subject in a building is lit from head to toe. However, this type of beam has a tendency to backlight in smoke and fog. The MX 431 has an obvious rectangle in the center of its beam but no dark spots or lack of concentricity.
The MX-431 will give the officer a great advantage in an alley search. The edges of the spillbeam are bright enough to still be intimidating. This is the kind of light I like for multiple suspects or on a weapon mount. This is especially a flashlight for tactical shooting because it illuminates a large chunk of periphery.
Leupold uses a True White LED, which rendered great contrast when using more rods for photoreceptors than cones. Some LED flashlights render confusing colors. I appreciate Leupold for using a high end LED.
LEDs are the best strobing instruments because they fire instantly, unlike filament or gas lights which take longer to reach peak illumination. The other advantage is the durability of the LED. This one is in a completely sealed module which is designed to be resistant to disassembly. It is firmly mounted and the entire flashlight package can handle one of those, “I left my flashlight on the hood and drove away” shocks with impunity.
The MX-431 uses a rotating bezel to access the various features, which are strobe, full brightness, reduced brightness and SOS. The bezel is quiet. One feels the clicks, which I understand actually use a magnet, rather than hear them. Using a magnet has allowed Leupold to seal the internal components.
The tail switch has a momentary, constant on and lockout function. Despite the heavy knurling, it was still a two-handed operation to lock or unlock. This tailswitch also fits several other brands of flashlights.
At its brightest setting, the peak output is 175 lumens. The strobing function is enhanced by the broad beam. Again, think multiple suspects, vehicle stops and crowd control. The low setting is 10 lumens, which is perfect as a work light. It proved to be very good at non tactical tasks like evidence gathering. I’m not sure what the SOS function is for, except that a set of batteries can make this light flash for 64.5 hours.
It appears that Leupold grossly underestimated their runtime, or I have a superior set of batteries. Their estimate is 3.2 hours at 175 lumens. For this set of cells, that was a while ago. I would stick with the 3.2 hours for planning purposes, but I’m satisfied with its runtime.
I found it just as easy to wrap the palm around the bezel and rotate the barrel for the functions than the other way around. . There is a two cell tube available for this, which may be preferable for smaller hands. In fact, there is an MX-421, which has exactly the same functions and fewer lumens.
One can use the supplied tether from two different mounting points, the barrel area near the tailcap and using a grenade ring on the pocket clip. Incidentally, the pocket clip is another means to orient the light in total darkness. The clip is not attached as one would clip on a pen barrel; it is actually screwed on using Allen screws.
I found that the adjustable tether was good for magazine changes and turning door handles. This is the plus side of a heavy bezel; it always points down and is easy to require the grip. I managed to get some nighttime IDPA runs in with it. However, the MX-431 did not improve my mediocre score.
This is a good reason why the modular system works for me. I would use this one for duty and use the MX-200 bezel, which is smaller, for off duty. There is a MX-020 Two Cell Maintube, which will further downsize the product. All the bezels have the nice strong front ring, which can create a little off duty distance in a pinch.
Probably the greatest disadvantage to the modular bezel is the fact that the most useful model is also the heaviest. I would do whatever it took to lighten it a little. Additionally, one configuration should include a rechargeable system.
The Leupold MX-431 is an almost indestructible flashlight with deluxe features. It is best suited for the urban officer who does more vehicle stops and building searches that search and rescue operations. Its modular features, quality manufacture, and inherent strength make it a once-for-career purchase.
Leupold & Stevens Inc. is America’s oldest optics company. They are family owned and do most of their operations right in Beaverton, Oregon, USA. Their scopes represent what American industry excels in and their products are evidence of why pride in ownership still exists. The Leupold & Stevens Inc. MX-431 Modular Flashlight deserves the Leupold name.