SureFire is a renowned name in the world of tactical lighting and firearms accessories, with a history that dates back to the late 1970s. The company was founded by Dr. John Matthews, a visionary engineer and entrepreneur with a passion for innovation in lighting technology and firearms equipment. SureFire’s journey began with a groundbreaking invention: a laser sight for firearms, designed to improve accuracy and target acquisition for law enforcement and military personnel. This pioneering product set the stage for SureFire’s future success and established the company as a trailblazer in the industry. As the years went by, SureFire expanded its product line to include weapon lights, flashlights, suppressors, and various other tactical tools and accessories. Their weapon lights, in particular, became highly sought-after by professionals and enthusiasts alike. Around six months ago Surefire sent me their new M640DFT-PRO Weapon Light to test and evaluate.

More Surefire @ TFB:

• SureFire Launches XSC-B Subcompact Handgun WeaponLight
• Mount Up: B&T USA And SureFire Suppressor Mounting System Collaboration
• The Surefire Adapter Carbon Scraping Tool (ACST)
• Surefire’s Newest, Lightest Rifle Can Ever: The SOCOM 65-Ti

With the M640DFT-PRO SureFire also sent me the SRO7 momentary/constant on the remote tape switch and the DSE click style/tape switch tailcap. While these are separate products I think they all complement and enhance the use and practicality of the M640DFT-PRO and should be strongly considered if you’re buying the light to throw on a rifle. 

The SureFire M640-Pro Weapon Light was provided by Surefire for this review and while I am allowed to keep the product indefinitely, this will not change my opinion on this product or any of SureFire’s current or past offerings.  

I have been using the M640-Pro Weapon Light on my primary AR-15 for around 6 months now and it has seen several range trips both at day and night along with a pretty consistent nighty use by myself to look around my backyard. I have taken it on a few hikes that went into the evening as a serious backup to my headlamp. I have also taken it to the Tactical Games where it sat on my rifle through every event including a fast-paced, low-light clearing stage through an old nuclear power factory. 

Manufacturer Specs – SureFire M640-Pro 

• HIGH OUTPUT – 700 lumens w/ SF18650B; 600 lumens w/ two 123 lithium
• RUNTIME – 2.75 hours w/ SF18650B; 1-hour w/ two 123 lithium
• PEAK BEAM INTENSITY – 100,000 candela w/ SF18650B; 90,000-candela w/ two 123 lithium
• BATTERIES – One SF18650B rechargeable (incl.) or two 123A lithium
• SWITCHING – Click tail cap
• LENGTH – 5.9 in (15 cm)
• DISTANCE – 632 meters w/ SF18650B; 600 meters w/ two 123 lithium
• CONSTRUCTION – Aluminum
• FINISH- Mil-Spec Hard Anodized
• WEIGHT W/ BATTERIES – 5.5 oz (156 g)
• BEZEL DIAMETER – 1.258 in (3.19 cm)
• LIQUID INGRESS PROTECTION – IPX7

Independent Specs – SureFire M640-Pro 

 

While I am only a sample size of one, I wanted to do some digging around online and see if there were any discrepancies on the specs of the M640-Pro in regards to output, runtime, or weight as sometimes manufacturers will embellish these numbers. Aside from a few rudimentary tests, I do not own the equipment necessary to perform any “Lab” quality tests so I will be referencing a lot of the work from Low Light Defence.com as these guys put out some great data. 

HIGH OUTPUT – 845 Lumens w/ SF18650B

RUNTIME – 205.22 Minutes 

CANDELLA – 84,000

DISTANCE – Depends on Target 

WEIGHT W/ BATTERIES ( M640-Pro with 1913 Mount)  – 5 ⅞ oz (167 grams) 

WEIGHT W/ BATTERIES ( M640-Pro with 1913 Mount, DSE, SR07) 8oz (228 grams)

Output/Runtime 

While the initial output is higher than SureFire states, it will drop pretty drastically after the 0:01:15 minute mark and will completely plateau to 460is lumens for a considerable amount of its runtime and will slowly dip to below 100 lumens after a staggering 2:40:00 minutes of runtime. 

Candela 

While it seems to have never hit the 100,000 mark stated by SureFire, the M640DFT-PRO does have an output of 84,00 initially with an average of 79,000 after the first 30 seconds. 

Distance

Personally, I hate when I see someone testing a light on a white subject like a car or a house or an IPSC target. While this can display the absolute reach of a light, it’s not very realistic so I decided to conduct my own test for this section. I simply set up a man-sized target wearing a green jacket and a Multicam plate carrier with a reflective patch on the chest. My goal was to have a more realistic target but still have a small reflective component for easy identification for myself. I also used two other lights during this test to help demonstrate the reach and hotspot of the M640DFT-PRO. The two other lights used were the Olight Odin Mini and the Streamlight TLR-1HL. While the TLR-1 HL is more likely to go on a pistol than a rifle, I figured it would be interesting to see the difference anyway. Note that all images of the target at distance were taken with a 200mm lens with the same camera settings for all images. 

The Target

50 Yards

100 Yards

150 Yards

200 Yards

300 Yards

While my test was by no means perfect as there was a lot of humidity in the air the night I did this test, I think a more realistic test like this is important. I also think it’s pretty obvious that the SureFire M640DFT-PRO with its high Candela has some pretty impressive reach on it. Keep in mind the Lumen output for the Olight and the Streamlight were rated to be over 1000, but in a test like this, more Candela is key.

Weight 

I used my kitchen scale for cooking so these numbers could be off but if they are it’s not by much. 

This longer format review will continue in Part 2