Surefire C2 experts— I have a bunch of questions (and a story)

For some reason or another I felt like looking up some info on my old C2. I came across some old threads from this forum and saw that they are fairly customizable. Now I am down the rabbit hole and have a bunch of questions. They relate to a few different boards, and I didn't think it would be appropriate to spam my questions throughout CPF.

I've had this light since approximately 2006. I'm not really a huge flashlight person, but I wanted something that was extremely bright for it's size. Surefire seemed like the best way to go at the time. This was the most expensive flashlight I've owned to that point. Even to this day, I only have one other "nice" flashlight (Surefire Mini Scout). I've changed out the headlamp on the C2 a couple of times, and it currently has a KX4 LED headlamp on it. Now, after looking at it some more without the red light filter, I think I want to switch back to the original bezel.

The problem is that I prefer LED over incandescent. So, my first, multi-part question is...

1. Is there a high-lumen LED headlamp assembly available that has a prioritization on throw (that would fit inside the OEM C2 bezel)?
-or is it possible to remove the lamp from the KX4 and insert it into the OEM C2 bezel?

The second set of questions concerns lithium-ion batteries in the C2. I've been using 18650 AW batteries for about 3 years for vaping, so I am familiar with charging and general safety.

2. Would a 17670 battery work in the C2? I read somewhere that the voltage range was 4.x-9.0.

3. Would I see an increase in run time and/or output?

It's been a long while since I bought this flashlight and I don't really see a need to buy another. I like the features (or lack thereof), construction, and size. Reading the old posts from 2010, I noticed that it was a popular flashlight.

4. Has the C2 withstood the test of time, or has it been eclipsed by newer makes/models (within the same class)?

Finally, since this is my first post and I'm asking a great deal of questions, I'll end with a moderately funny flashlight story.

I was doing TDY (Army Reserve) at a reserve center in Grand Prairie, TX to reclassify to 68W (Combat Medic). During the final portion of the training we were required to do a "low-viz" or "night stick." It involved the use of either very little ambient light, or we could use a flashlight with a lens filter. The instructors recommended blue over red because the veins would be slightly more visible.

I looked at a few different places and didn't find a light I really wanted. REI had some Petzl headlamps, but my unit probably would have had a conniption fit if they saw me wearing a 1/5" jet black elastic band strapped to my helmet. I eventually saw that Surefire made a helmet mounted headlamp (HL1 series, blue/white) which was fairly inconspicuous— much less so than a huge black swath).

It was getting fairly late in the afternoon by the time I discovered the Surefire. I'm a very impatient man, and when I find something I want, I want RTFN. So, I decided to google retailers to see if anyone carried it. Gander...no, REI...no, Cabelas...no. So I tried a map search for "Surefire," hoping that a dealer would pop up. Sure enough, "Surefire LLC" or some such popped up on the map. Holy poop! A dedicated Surefire storefront! and it was only 30 minutes away!! I couldn't believe it. It was getting late so I called ahead to see if I could make it before they closed.

A guy answered the phone and I asked when they closed. He said they were closing in about 30 minutes. "Oh jeez (insert MN accent), I'm about a 30 minute drive from your place. I hope I can make it before your store closes." Sensing my concern and that I really wanted to buy a Surefire product that day, he asks, "is it an emergency? I could keep the shop open for a little while longer." I say, "not really, but I would really like to pick up a headlamp today." He then says, "we don't have any of those. We sell rubber band guns." I just hang my head and say bye.

After I got off the phone, wallowing in defeat, I recanted the conversation. "Is it an emergency?" Whoa, wait up! Did he just ask if I had a rubber band gun emergency?! :duh2::duh2: WTF. Is that a thing? What kind of situation would I need to be in to desperately require a rubber band gun?!

Anyway, I went to one of the nearby Army bases the following day and found it at the PX/Clothing and Sales.

Thanks for listening!

Truegrave said:

1. Is there a high-lumen LED headlamp assembly available that has a prioritization on throw (that would fit inside the OEM C2 bezel)?
-or is it possible to remove the lamp from the KX4 and insert it into the OEM C2 bezel?

The second set of questions concerns lithium-ion batteries in the C2. I've been using 18650 AW batteries for about 3 years for vaping, so I am familiar with charging and general safety.

2. Would a 17670 battery work in the C2? I read somewhere that the voltage range was 4.x-9.0.

3. Would I see an increase in run time and/or output?

It's been a long while since I bought this flashlight and I don't really see a need to buy another. I like the features (or lack thereof), construction, and size. Reading the old posts from 2010, I noticed that it was a popular flashlight.

4. Has the C2 withstood the test of time, or has it been eclipsed by newer makes/models (within the same class)?

Click to expand...

1) When using the original C2 bezel, YES!
the bulb module is generally known as P60 dropins. You can find that there are a few people in this forum that makes these dropins, namely Vinhnguyen54, Nailbender & some others.
I am not too sure about the KX4 bezel so let others chip in.
For max throw, u would wanna look at the XP-G2 dedomed with smooth reflector.

2) There are some variant to 17mm cells, so some may fit while some won't.
A 16650 is your best bet to try on an unbored battery tube. Or you may sent your light to some professional to bore them out to 18mm so u can use 18mm cells..
Most dropins are optimized to run on a single lit-ion cell (3 to 4.2V), so make sure that you are running them with the correct battery.

3) Depending on the dropin that you select, they should easily dwarf the output of the stock P60 Surefire dropin. So yes, i would say you should be able to get a significant runtime & output increase.

4) The P60 dropins lights are known for its versatility: new driver? Do a driver swap. New emitter? Do an emitter swap..
You can always get the newest stuff in your C2..

Two places I would recommend for drop ins would be Lumens Factory and Mountain Electronics. Lumens Factory has an XP-G2 drop in in either Neutral White or 90+ CRI, in either single or multi mode. Output is between 350-400 lumens. If color recognition is important, get the 90+ CRI version.
Mountain Electronics sells a CUXM/CUXP drop in in your choice of XM-L2 at around 1000 lumens, or Nichia 219B at 400 lumens. Again, if you want improved color recognition, get the Nichia 219B version.

I have both of the above mentioned, one in a G2 and one in a 6P, and love them both. I run them with 16650 cells, and they work great.

1. Is there a high-lumen LED headlamp assembly available that has a prioritization on throw (that would fit inside the OEM C2 bezel)?
-or is it possible to remove the lamp from the KX4 and insert it into the OEM C2 bezel?

There are a number of different drop ins available for the Surefire C2. You would need to use your original bezel since you cannot dismantle the KX4. While there are a few dozen choices of P60 drop ins, I always recommend Malkoff Devices M61 because they are just as reliable as your Surefire and can be had for around $50. You have the choice of different tints, and can also choose whether you want single mode, or multiple mode. They aren't 100% focused on throw, although they do have a nice hot spot that will reach further than your KX4.

single mode cool:
https://malkoff-devices.myshopify.com/products/m61-mod-to-fit-surefire-and-malkoff

Three mode (LMH) cool:
https://malkoff-devices.myshopify.com/products/m361-lmh-low-med-high-to-fit-surefire

single mode 219B:
http://www.illumn.com/malkoff-devices-m61l-219b-v2.html

Single mode neutral:
http://www.illumn.com/malkoff-devices-m61n.html


The second set of questions concerns lithium-ion batteries in the C2. I've been using 18650 AW batteries for about 3 years for vaping, so I am familiar with charging and general safety.

2. Would a 17670 battery work in the C2? I read somewhere that the voltage range was 4.x-9.0.
Yes, a 17670 battery will physically fit. It should also be compatible with most LED drop ins/conversions. The Malkoff M61 has an input range of 3.4v-9v. A 17670 provides 4.2v fresh off the charger, with a nominal voltage of 3.7v. Be careful on which drop in you choose. Some drop ins only have an input range of 3.0v-4.2v and will not be able to handle the voltage of two CR123 batteries (in the event you didn't have a fresh 17670 handy and needed to use disposable batteries).

3. Would I see an increase in run time and/or output?

Yes to both. Your KX4 will be blown away by the Malkoff M61. The M61 provides 300 lumens for at least 1.5 hours, then provides a slowly decreasing output for another few hours. Your KX4 runtime leaves a lot to be desired, and is only rated for either 80 or 120 lumens, depending on when it was made.

It's been a long while since I bought this flashlight and I don't really see a need to buy another. I like the features (or lack thereof), construction, and size. Reading the old posts from 2010, I noticed that it was a popular flashlight.

If you like the simplicity of the C2, I think you'd be extremely happy with a single mode M61. You just need to pick which tint you prefer.

4. Has the C2 withstood the test of time, or has it been eclipsed by newer makes/models (within the same class)?

It is a favorite of anyone who knows flashlights for a good reason: the ergonomics, build quality, durability of the finish, simplicity, and unlimited upgrade ability makes it a keeper.

Awesome replies so can't add anything and new to the c2 myself. For me it has certainly stood the test of time as I got a couple of them in the last month or two! My fav surefire and run one on Sanyo 16650 fuel 4.35v.

This I also have the Malkoff L/M/H drop in(always starts in low) in a very nice 4000k neutral. A highly recommend ....




That one as is, then my other C2 with a z32 cryos bezel and triad tail cap(oveready), bored for 18650 so an INR cell inside to feed a P60vn (quad xp-l 5000k)




As cland said, unlimited upgrade options



:welcome:

Thanks for all of the great replies!

I've done some more looking and I found a couple options right out of the gate. I just need to decide which direction I should go. I saw the Overready Mini Turbo head and complete flashlight. The numbers are very impressive! The only downside would be that I would have to buy their custom C2 or find somewhere to have my C2 bored. The M2 head isn't too much bigger and I think I could live with the slight increase in size. The other option I found was mentioned above— the Malkoff M61 drop in. I looked at the stats and it uses the XP-G2 emitter which was mentioned by DellSuperman. It doesn't have the smooth reflector and isn't dedomed though.

Timothybil suggested the Mountain Electronics XM-L2 drop in. I haven't researched it yet, but that sounds like a very good choice if I wanted to stay closer to a stock configuration. I'll definitely look at that one next. I wonder if it needs to be direct drive because of the power requirements.

As a side note, I saw Surefire has a 500 lumen head for $200+. The choices listed by you guys are much more appealing though. I also saw they had their own version of 18650 protected batteries and charger. I wonder if they would be an upgrade to my AWs and my Trustfire TR-001?

I just need to decide if I want the whole Overready flashlight, try to find someone to bore my C2 & build my own, or go with the drop in heads. Or just have two flashlights!

Thanks again for all the help!