If the Streamlight HL-X is the “hard-hitting value” choice, then the SureFire M640U is the “pay once, cry once” option people keep circling back to. However, the price only makes sense if the performance, durability, and mounting system truly feel like a step up. So, in this SureFire M640U review, we’ll cover the published specs, what it feels like on a real rifle, and how to set it up without making it complicated.
What the SureFire M640U Is
The SureFire M640U Scout Light Pro is a premium weapon-mounted light built around a simple idea: reliable, weapon-grade illumination with a mounting system that’s easier to position correctly. In other words, it’s not trying to win on gimmicks. Instead, it’s trying to win on consistency.
On SureFire’s product page, the headline specs are straightforward:
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1,000 lumens
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11,300 candela
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1.25 hours runtime
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213 meters distance
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two CR123A batteries
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click tailcap
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5.5 inches length
Additionally, SureFire has a dedicated guide explaining how to mount and adjust the Scout Light Pro system.
SureFire M640U Specs (Beginner-Friendly Translation)
Here are the numbers people care about—and what they mean without the flashlight-nerd headache.
Output and intensity
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1,000 lumens = strong total light output for indoor and typical outdoor work.
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11,300 candela = a practical level of intensity for identification and control.
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213 meters = useful reach for real home/property distances (not “Turbo throw” territory).
Runtime and power
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1.25 hours on high using two CR123A batteries.
So what does that feel like?
Indoors, 1,000 lumens is plenty—almost always. Outdoors, it’s still very usable; however, it’s tuned more for practical ID than extreme distance beam games.
For a third-party spec mirror, Primary Arms repeats the same output and candela figures.
What the SureFire M640U Is
The SureFire M640U Scout Light Pro is a premium weapon-mounted light built around a simple idea: reliable, weapon-grade illumination with a mounting system that’s easier to position correctly. In other words, it’s not trying to win on gimmicks. Instead, it’s trying to win on consistency.
On SureFire’s product page, the headline specs are straightforward:
1,000 lumens
11,300 candela
1.25 hours runtime
213 meters distance
two CR123A batteries
click tailcap
5.5 inches length
Additionally, SureFire has a dedicated guide explaining how to mount and adjust the Scout Light Pro system.
SureFire M640U Specs (Beginner-Friendly Translation)
Here are the numbers people care about—and what they mean without the flashlight-nerd headache.
Output and intensity
1,000 lumens = strong total light output for indoor and typical outdoor work.
11,300 candela = a practical level of intensity for identification and control.
213 meters = useful reach for real home/property distances (not “Turbo throw” territory).
Runtime and power
1.25 hours on high using two CR123A batteries.
So what does that feel like?
Indoors, 1,000 lumens is plenty—almost always. Outdoors, it’s still very usable; however, it’s tuned more for practical ID than extreme distance beam games.
For a third-party spec mirror, Primary Arms repeats the same output and candela figures.
Pros & Cons
| Pros | Cons |
|---|---|
| Premium build quality and proven duty-grade reputation | Higher cost than many value lights with similar lumens |
| Balanced beam for indoors (1,000 lumens / 11,300 candela) | Not a high-candela “Turbo” throw-focused beam |
| Scout Light Pro mount is adjustable across common rail setups | Uses CR123A (not the 18650 Dual Fuel format) |
| Simple click tailcap: easy momentary and constant-on control | Some users add accessories/switches, increasing total cost |
SureFire M640U Beam Pattern: Indoors vs Outdoors
The SureFire M640U is often described as “balanced.” That can sound vague, so let’s make it real.
Indoors
Indoors, the SureFire M640U combines 1,000 lumens with 11,300 candela, which is strong without feeling like a laser pointer. As a result, you usually get:
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clear ID at room distances
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less tunnel vision than ultra-throwy beams
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useful spill for edges and corners
Outdoors
Outdoors, the 213m distance rating means the beam is capable for realistic home/property distances. However, if your main goal is long-range throw, the Turbo models later in your series will be a better match.
SureFire M640U Mounting: Why Scout Light Pro Is Different
Mounting is one of the sneaky reasons people pay for SureFire. It’s not just “the light.” Instead, it’s also the system.
SureFire’s mounting article explains how to install and adjust the Scout Light Pro mount on a long gun.
Meanwhile, Primary Arms highlights the integrated mount’s versatility for M-LOK and Picatinny setups.
Why this matters for beginners:
If a light sits in the wrong spot—too far back, too snaggy, or too awkward to activate—you won’t run it well. Therefore, a mount that helps you dial placement faster is not a small thing.
SureFire M640U Switching: Tailcap Feel Under Stress
SureFire lists the SureFire M640U switching as a click tailcap.
In practice, that’s great because it stays simple:
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momentary when you want it
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constant-on when you need it
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fewer “mode surprises,” especially under stress
Even better, a tailcap setup is easier to troubleshoot. If the light doesn’t activate, you’re checking fewer variables.
Reliability & Durability: What SureFire Is Selling You
SureFire’s pitch is “built for hard use.” In the real world, that often means the body and mount feel like one unit, and the whole package feels less “fussy.” Because of that, many shooters treat it like a long-term buy rather than a temporary experiment.
Retail listings commonly mirror the published spec set (1,000 lumens / 11,300 candela / 1.25 hours / 213m).
SureFire M640U Setup Recipes:
Recipe 1: Home defense
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Mount: 11 o’clock / 1 o’clock
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Activation: tailcap
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Goal: clean activation + low snag profile
Recipe 2: Training rifle
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Mount: 11/1 or 12 depending on grip
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Activation: tailcap first, then upgrade later if needed
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Goal: repeatable control without thinking
Recipe 3: “One rifle, many jobs”
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Mount: forward enough to reduce shadowing
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Activation: tailcap simplicity
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Goal: reliable light you don’t baby
SureFire M640U vs HL-X vs Mini Scout
SureFire M640U vs HL-X
HL-X often brings more reach-per-dollar. However, the SureFire M640U brings a refined mount ecosystem and a premium feel many people trust long-term.
SureFire M640U vs Mini Scout Light Pro
The Mini Scout class often wins on compactness. Meanwhile, the SureFire M640U is the “full-size” option that feels more substantial on a general-purpose rifle.
Why a Weapon Light Matters
A weapon light isn’t about looking cool. Instead, it’s about identifying what you’re looking at in low light.
At the same time, technique matters. For example, Streamlight has written that searching with a weapon light can create muzzle-discipline concerns, and it discusses using a handheld light for searching to reduce risk.
AmmoLand makes a similar point: using a weapon light to search can mean you’re muzzling non-threats, so a handheld is often preferred for searching.
So, the simple takeaway is:
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handheld light = search and move
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weapon light = confirm and identify when the rifle is legitimately oriented
FAQs
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Is the SureFire M640U bright enough for home defense?
Yes. SureFire lists the SureFire M640U at 1,000 lumens, which is plenty for typical indoor distances. -
What is the candela rating on the SureFire M640U?
SureFire lists 11,300 candela peak beam intensity. -
What is the beam distance?
SureFire lists 213 meters. -
How long does it run on high?
SureFire lists 1.25 hours runtime on high. -
What batteries does the SureFire M640U use?
SureFire lists two CR123A lithium batteries.
Final Thoughts
If you want a premium light that feels like it belongs on a working rifle, the SureFire M640U makes a strong case. It isn’t trying to be the throwiest beam in the world. Instead, it delivers practical specs, a balanced beam, and a mount system that makes “getting it right” easier.
Just as importantly, the SureFire M640U is the kind of light you buy because you want consistency, not because you want to tinker forever.
Links
Streamlight ProTac Rail Mount 2
Streamlight ProTac HL-X Rifle Light Review
Lumens vs Candela for AR-15 Flash Lights
Best AR-15 Flash Lights for Home Defense