Surefire Shotgun light

The Surefire 618LFG shotgun grip replacement light uses the LED 6P host, runs off of 2 CR123s with an 80lm output, but only last for 3 hours. This is just like the Original LED 6P, but has 8 hours of runtime cut off. I dont get it could someone explain please. I plan on buying this and mount it on my remington 870. I want to change the lamp assembly to the M60, is this even possible? I wonder what the run time would be like with the M60 haha.

SF 618LFG

FEATURES

• Solid-state, recoil-proof light emitting diode (LED) generates 80 lumens of blinding white light
• Produces tactical-level light for over three hours on a single set of SureFire lithium batteries

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SF 6PL

And it continues producing useful light levels for an impressive 11 hours on a single set of batteries

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If you'll notice, it says "tactical level light"... I read somewhere that SF's definition of 'tactical level' is 60 lumens or more. It uses the same P60L as the 6PL or any of the other C/P/G LED variants. The difference in the runtime ratings is because the 6PL says 'useful' light output. Useful (while debatable) would be around 1-5 lumens.

matt0 said:

If you'll notice, it says "tactical level light"... I read somewhere that SF's definition of 'tactical level' is 60 lumens or more. It uses the same P60L as the 6PL or any of the other C/P/G LED variants. The difference in the runtime ratings is because the 6PL says 'useful' light output. Useful (while debatable) would be around 1-5 lumens.

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I dont know if that is true because the 6P usefull light is 80lms bottom line (look at the specs) and it does run for 11 hours. The weapon light puts out 80lms for 3 hours. Put whatever name in front of it but its still 80lms for 3 hours.

hubbytuby said:

I dont know if that is true because the 6P usefull light is 80lms bottom line (look at the specs) and it does run for 11 hours. The weapon light puts out 80lms for 3 hours. Put whatever name in front of it but its still 80lms for 3 hours.

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If you download SF's 2008 catalog you'll see a runtime graph showing the 6PL dropping out of regulation just after 3 hours and dropping under 10 lumens at about 4.5 hours. FYI

My question is why does it drop so fast compared to a normal 6P? And would a Malkoff M60 fit in it?

If we put aside the factors of human body enhanced thermal management (by holding the flashlight you are wicking away heat from it using your blood circulation as a heat sink) vs the light being attached to a firearm which itself could well be getting rather hot, and when it isn't, there isn't a good thermal path from the Lamp Module through the WeaponLight housing and to the firearm.

So lets assume that the thermal characteristics of a 6PL in hand and a 618LFG are similar.

The difference in runtime 'ratings' is one of application. For a handheld flashlight users can make use of light output beyond the regulated output (beyond 3 hours of tactical level output). For a WeaponLight the user requires the tactical level output only.

My guess is there is also a bit of legal/prudent conservatism there as well. A weapon mounted light is a SERIOUS SOCIAL light that is not going to be used for power outages. The lower runtime probably has to do with both actual bright light levels, less heat sinking through a hand and a little conservatism to make you change the batteries more often due to the intended use. 3 hours is a heck of a long runtime for a weapon light.

Does it really matter if it's 8 or 3 hours? In either case, it's a lot more runtime than a weapon light really needs.

What I find welcome is the shift in our concerns today versus a couple of years ago. Back in the incan days, my biggest concern for shotgun light was shock isolation. Brightness was second and whatever I could get run time was what I got. Now, we are approaching the technological point of determining what balance of brightness and run time I want. SI is a distant concern.

If you want a full 80lm for 8 hours, get the Malkoff M60LL!