February 25, 2019
By Guns & Ammo Staff
Until 2006, halogen or xenon bulbs were the industry standard in firearm mounted lights. Usually placed in lamp assemblies or a shock-resistant housing, early ones produced 60 lumens of light for nearly an hour or 120 lumens for almost 20 minutes when backed by a pair of CR123 lithium batteries.
The downside to these bulbs was that they could break when taking hard bumps or enduring shock when attached to a machine gun. Or they’d burn out at the most inopportune time, and without warning.
In 2006, Surefire introduced a new light that was designed for use on firearms: the Scout Light. The M600A was smaller, sleeker and lighter than models before it. It also incorporated a light emitting diode (LED), then-new technology for a gun light.
The primary advantage offered by the LED emitter was reliability. The LED was nearly indestructible and had a life span measured in thousands of hours instead of mere minutes. The secondary benefit was its extended, regulated battery life thanks to Surefire’s small, on-board circuitry.
The first M600A was not without flaws. At the time, light output was limited to 65 lumens, and the light was a bluish-white hue. The light could not be filtered to produce illumination in the infrared (IR) spectrum either. As a temporary solution, Surefire offered a kit with a second head that housed a traditional xenon lamp assembly and a flip-cap (IR) filter dubbed the M600B. It was short lived as technology remedied shortfalls.
The output of the Scout Light was soon bumped to 120 lumens and then again to 200 lumens of ultra-white light with the subsequent M600C model. With a new KX2C head, total internal reflection (TIR) lens and high-output LED, the M600C outshined its competition and was brighter than its 200-lumen rating. It earned its place on the small arms of the U.S. military and law enforcement.
Surefire’s evolution of the Scout Light didn’t plateau there. Engineers continued to develop its LEDs and lens technology, producing new models with increased output, battery life and acceptance of accessories, which included remote pressure switches and offset mounts.
A single-cell Mini Scout Light labeled the M300 was developed next, as was Surefire’s wide-lens Fury model. These were followed by the V-series, aka “Vampire,” with IR output. A twist of the bezel alternates between white and IR illumination.
The white light models were succeeded by the M600 Ultra that produced 500, 600 and currently 1,000 lumens. Others, such as the M600IB features Surefire’s IntelliBeam technology that automatically adjusts output ranging from 100 to 600 lumens courtesy of an intelligent sensor and microprocessor.
The Scout Light’s continued evolution has only been hindered by its source of power: the battery. The lithium CR123A battery was the key to Surefire’s initial success, but Surefire’s latest iteration, the M600DF (“DF” refers to dual fuel), is rated at 1,200 lumens on a pair of CR123s. However, when an 18650 lithium-ion rechargeable battery is used, output rises to 1,500 lumens for 1½ hours. Surefire had to enlarged the circumference of the body slightly to accommodate the 18650, but it goes mostly unnoticed.
Aside from the power and runtime increase, the allure of 18650 rechargeable is peace of mind. When I step out the door, the clock has restarted as my light is operating on a fresh battery. Putting new CR123s in the light each time I went out would cost me.
The new M600DF comes complete with a Picatinny rail mount, an 18650 rechargeable battery, a charging station equipped to charge a pair of batteries, cables for both, a traditional wall socket as well as a 12-volt vehicle adapter. Many accessories are available to support and customize the new Ultra Scout Light. Build your M600DF kit at surefire.com
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