User Panel
User Panel
User Panel
|
Posted: 7/2/2020 11:39:02 PM EDT
Let me start this by saying this isn't a slam piece against Surefire. This is simply a warning to consumers that you shouldn't waste your time and money on the M640DF (which is the Pro version of the M600DF) until Surefire gets their obvious problems with this model sorted out. If you're too impatient to read the whole thread, then read this:
1. This is not an isolated incident or a "lemon" 2. One of these lights have already been sent back to Surefire for warranty work and they sent it back still busted. This started with Surefire's leaked 40% off coupon code. Me and two of my friends all bought M640DF's, two tans and one black. The friend who ordered the black got his first because the blacks weren't back-ordered. When he got his he noticed that it would dim or flicker whenever he dropped the bolt on his Bren 2MS that he had it mounted on. This happened with both 18650 batteries and CR123s. During firing it was even worse: the light would behave very strangely, it would dim or cut off completely, and he would have to press the button multiple times before it would return to full brightness. Unfortunately I have no video of this happening. He sent it back to Surefire for warranty and Surefire turned it around pretty quickly. I think it was about a week and a half before he got his light back which is pretty impressive. What wasn't impressive is that the light was only halfway fixed. When he got it back it functioned fine with 18650s, even during firing. However, with CR123s, the problem still persisted. See videos:  M640DF Black - dimming severely upon firing (CR123s)  M640DF Black - dimming on bolt drop (CR123s) Direct links: vid1 vid2 After this he requested a refund from Surefire and Surefire has said they will grant him a refund. Although he is still waiting on the money, it hasn't been that long and I think he will get his money. 1/2 |
|
|
|
Posted: 7/2/2020 11:39:49 PM EDT
[#1]
2/2
During this time the other friend who ordered a tan 640DF received his A couple weeks ago I finally received my tan M640DF and I am having the same issues as my friend who had the black 640. Before I received mine I was hoping that my friend's defective light was just a "lemon" or a fluke. Now that this is no longer an isolated incident there is reason to believe that something is very wrong with the manufacture of these M640DFs, whether it is poor quality control or a fundamental flaw in the design. My light is flickering when I drop the bolt on an AR with 18650's, and dimming significantly with CR123s. I haven't had a chance to try shooting with it yet, I will do that either tomorrow or Saturday, but if it's malfunctioning from just dropping the bolt it's obviously not going to do any better from live fire. Video:  M640DF Tan - dimming with CR123s Direct link since the youtube embeds aren't working: https://youtu.be/B3M-jeRNsOE You can draw your own conclusions, but the tl;dr is that out of three of these lights purchased, two of them were defective out of the box, and the one that went back to Surefire for warranty was still defective when it came back. |
|
|
|
Posted: 7/3/2020 9:59:43 AM EDT
[#2]
Could it be a switch issue?
|
|
|
|
Posted: 7/3/2020 10:04:52 AM EDT
[#3]
Did Surefire supply the 18650's?
Paladin |
|
|
|
Posted: 7/3/2020 10:41:28 AM EDT
[#4]
This is almost certainly a spring tension issue on the cap side. Long ago I got my first led flashlights from China and they’d behave like this when gun mounted just from the mass of the battery reacting to recoil and it would hop off the compressed spring and the light would flicker. If it’s a multimode light, this changes the brightness setting. Since 18650 and 2x cr123 are different lengths, this will be amplified when using the shorter batts.
|
|
|
|
Posted: 7/3/2020 11:08:48 AM EDT
[#5]
It’s happening with the supplied Surefire branded 18650, Surefire branded CR123s, as well as Titanium CR123s and Nightcore 18650s.
|
|
|
|
Posted: 7/4/2020 12:18:38 PM EDT
[#6]
Issue is confirmed on my dual fuel pro as well. It flickers momentarily when running the bolt home. Incidentally the switch supplied with it (Z68), seems to flicker less than the DS07. So the tension suggestion maybe spot on, but not sure if say pulling on the tailcap spring would fix the issue. At all or only temporarily. Really no excuse for this as SFs are for real world use and these issues completely compromises that.
Havent gotten around to shooting it. To the op, so one of the three was perfetly fine? mind seeing if there are any difference in the tail cap between the defective ones and the one that works? |
|
|
|
Posted: 7/4/2020 3:45:44 PM EDT
[#7]
Had this same problem with the stream light tlr 7 when it came out. I cut a piece of rubber band and put it in between two coils of the spring and it fixed it for good. I’d bet you could do the same with this and fix it.
Not saying you should have to but I’m ok with mine since i did this. Not a big deal in my book if it works from then on 100% |
|
|
|
Posted: 7/4/2020 5:14:55 PM EDT
[#8]
I haven't had this happen with mine, mounted on an AK until my RPM ACR handguard arrives.
The only difference in the 640 and the 600 is the mounting provision on the body, correct? The tailcaps and heads are the same |
|
|
|
Posted: 7/5/2020 1:01:02 AM EDT
[#9]
Shit, my regular 600DF did that. Both of them. My nightstick 500xl does it too. Olight, Armytek, and Modlight dont.
|
|
|
|
Posted: 7/6/2020 4:16:32 PM EDT
[#10]
Quote HistoryQuoted: Havent gotten around to shooting it. To the op, so one of the three was perfetly fine? mind seeing if there are any difference in the tail cap between the defective ones and the one that works? Actually, my friend that had the tan one that he said worked fine had only ever tried it with 18650s. He tried it for the first time with CR123s yesterday and it had the same issues as mine and my friend who had the black one. So from the three of our lights, none of them work as advertised. Bravo Surefire. I was told it is an issue with the tailcap spring tension which is loose to begin with an is exacerbated by using CR123s which are shorter than an 18650. Apparently cutting a foam earplug in half and sticking the tip under the tailcap spring is supposed to help. I just wonder if that will be enough for my Scar 17 once I get the barrel back and get it back in action. If it has problems with the bolt dropping on an AR I can only imagine it would be worse with a Scar. |
|
|
|
Posted: 7/14/2020 11:36:15 AM EDT
[#11]
I had a tan M600DF. First time on the range, after roughly 120 rounds the light would no longer turn on. the head was not mounted in line or next to the flash hider (SF 4 prong). Got home and contacted Surefire. They said i was given an old 18650 that was a known issue. They sent me a new one (2 weeks later), and that would not work either. I even tried other 18650s (keep power from my two modlites) and that did not work. I gave them another call, and they said I "could" send it in and they will see if there was anything wrong with it. This was after asking me trivial questions like "are the batteries in backwards" and "is the light head screwed in all the way". Also, they were averaging 8 ~ 10 weeks for an answer once received.
I said screw it and got another modlite head. It was not worth my time to mess with it. |
|
|
|
Posted: 7/14/2020 12:05:50 PM EDT
[#12]
Quote HistoryQuoted: I said screw it and got another modlite head. It was not worth my time to mess with it. Yep, modlite makes a beast of a product and they specifically state that the light was designed to withstand the recoil impulse of the scar 17. |
|
|
|
Posted: 7/29/2020 2:01:10 PM EDT
[#13]
Surefire quality is not what it use to be, nor is there customer service.
|
|
|
|
Posted: 7/29/2020 2:12:09 PM EDT
[#14]
Hey I’m actually having the exact same issue! I thought it was bad batteries at first but I switched them out and put fresh ones in and my light dims considerably after shooting. I’ll be contacting surefire
|
|
|
|
Posted: 7/29/2020 11:49:27 PM EDT
[#15]
I can tell you all, I know for sure this is a tail cap spring issue, not making firm enough contact on the negative side of the battery.
Solution: remove tail-cap, and stretch out your spring! Thank me later. I’ve had that problem with so many lights, including my M600df |
|
|
|
Posted: 7/30/2020 4:57:31 AM EDT
[#16]
Quote HistoryQuoted: I can tell you all, I know for sure this is a tail cap spring issue, not making firm enough contact on the negative side of the battery. Solution: remove tail-cap, and stretch out your spring! Thank me later. I’ve had that problem with so many lights, including my M600df While this can be the problem it’s definitely not the issue with some of these. I tried that on both of mine. Whoever said that Surefire quality and CS aren’t what it used to be is correct. |
|
|
|
Posted: 7/30/2020 7:29:45 AM EDT
[#17]
Well, I can tell you for sure the problem is something simple like that. Shorts are not hard to find, and easy to create. It could be something as simple as too much anodizing on the threads, sand paper is your friend.
|
|
|
|
Posted: 7/30/2020 7:43:03 AM EDT
[#18]
Quote HistoryQuoted: Well, I can tell you for sure the problem is something simple like that. Shorts are not hard to find, and easy to create. It could be something as simple as too much anodizing on the threads, sand paper is your friend. That’s not an issue the end user should have to worry about on a $200-300+ flashlight. |
|
|
|
Posted: 7/30/2020 10:45:09 AM EDT
[#19]
Double post
|
|
|
|
Posted: 7/30/2020 10:49:16 AM EDT
[#20]
Quote HistoryQuoted: That’s not an issue the end user should have to worry about on a $200-300+ flashlight. I’m not trying to defend that fact. But, I do guarantee it is something simple. |
|
|
|
Posted: 8/4/2020 3:24:34 PM EDT
[#21]
Any updates on this? I have a M640DF that flickers and goes to a low power mode... both with a brand new and charged 18650 and new (2x) CR123As.
Planning to call SF, just wondered if anyone had updates. |
|
|
|
Posted: 8/5/2020 8:31:59 PM EDT
[#22]
my dual fuel would do this as well. I was using a pressure switch. I switched back to the z68 tail cap and have not had the issue anymore.
|
|
|
|
Posted: 8/7/2020 1:33:28 PM EDT
[#23]
Both of mine exhibit this issue. Also, the mount is garbage. No matter how much you torque the screw upon which if rotates to your preferred angle, the light can still move with minimal effort.
Has anyone actually put one of these through hard use? |
|
|
|
Posted: 8/7/2020 3:37:28 PM EDT
[#24]
Quote HistoryQuoted: Both of mine exhibit this issue. Also, the mount is garbage. No matter how much you torque the screw upon which if rotates to your preferred angle, the light can still move with minimal effort. Has anyone actually put one of these through hard use? My mount locks up solid. No issues there. I did reach out to SF customer services and they are sending me some parts in an attempt to resolve the issue. They said we could RMA the flashlight if it continues to exhibit the problem. Excellent customer service. |
|
|
|
Posted: 8/8/2020 5:01:33 AM EDT
[#25]
Quote HistoryQuoted: My mount locks up solid. No issues there. I did reach out to SF customer services and they are sending me some parts in an attempt to resolve the issue. They said we could RMA the flashlight if it continues to exhibit the problem. Excellent customer service. Thanks for sharing this info. If you grab the light while mounted, are you able to force it to move at all either towards or away from the rail? |
|
|
|
Posted: 8/8/2020 7:08:24 AM EDT
[#26]
New 600DF, EU-SR07, rear cap
With 18650b not fully charged had flickering / pulsing issues Fully charged no issues (holy crap it’s bright) Cr123 no issues Light securement no issues |
|
|
|
Posted: 8/11/2020 2:10:01 PM EDT
[#27]
I have 2 I haven't really used yet but when I function test them they both lightly flicker using pressure switch when I first press them. I haven't even fired with them yet. I thought it was normal
|
|
|
|
Posted: 8/17/2020 4:59:17 PM EDT
[#28]
Just got my M640DF, EU cap and SR07 pressure pad. Everything works fine with the clickable tailcap. However, when I put on the tailcap and pressure pad the light goes bright for a fraction of second and then goes dim. This is with the surefire red 18650. I put in a streamlight 18650 and it works perfectly. However, I talked to surefire and they said they are having issues with some of the "tan EU caps" and even if I can get a battery to work it won't be consistent and that something is wrong with the cap. They are sending a new tailcap and said if that doesn't solve it I would have to send back the entire light.
Very frustrating seeing that the light, tailcap and pad are big bucks....... |
|
|
|
Posted: 8/18/2020 7:36:12 AM EDT
[#29]
Quote HistoryQuoted: Just got my M640DF, EU cap and SR07 pressure pad. Everything works fine with the clickable tailcap. However, when I put on the tailcap and pressure pad the light goes bright for a fraction of second and then goes dim. This is with the surefire red 18650. I put in a streamlight 18650 and it works perfectly. However, I talked to surefire and they said they are having issues with some of the "tan EU caps" and even if I can get a battery to work it won't be consistent and that something is wrong with the cap. They are sending a new tailcap and said if that doesn't solve it I would have to send back the entire light. Very frustrating seeing that the light, tailcap and pad are big bucks....... Did you fully charge 18650 prior to “testing”? |
|
|
|
Posted: 8/20/2020 9:25:11 AM EDT
[#30]
Yeh, I put in a fully charged Streamlight 18650 and Surefire red 18650. Both solved the problem.......for a short time and then it went back to being bright for a fraction of second then to dim. The Surefire customer support told me even if I switched batteries and found one that worked it wouldn't remain consistent. He was adamant that they have known problems with tan/FDE UE tailcaps. Hopefully I will know today if my replacement tailcap arrives.
|
|
|
|
Posted: 8/23/2020 1:42:08 PM EDT
[#31]
brand new scout pro IR is doing this too. tried it first with a 17670 and it happened a few times during shooting, and the I went back to the two cr123 and it happened again. this is a black with stock clicky tail cap.
|
|
|
|
Posted: 8/30/2020 1:09:44 PM EDT
[#32]
Seen this post and made an acc to say im also having issues with the 600 series. My light does exacly the same thing as mentioned above. Surefire sent me a battery but it didnt help. After searching online I found that the surefire batteries dont have the best reviews as far as reliability so I bought 2 new nightcores to give it a try but problems were still there. When you push the button/pressure pad the light output is strong but slowly pulses down and gets very dim. Same with factory button. This looks like a common issue and warranty repairs sound like a gamble so are there any other reliable alternatives lights that use the 18650.
|
|
|
|
Posted: 8/30/2020 7:59:36 PM EDT
[#33]
Quote HistoryQuoted: Seen this post and made an acc to say im also having issues with the 600 series. My light does exacly the same thing as mentioned above. Surefire sent me a battery but it didnt help. After searching online I found that the surefire batteries dont have the best reviews as far as reliability so I bought 2 new nightcores to give it a try but problems were still there. When you push the button/pressure pad the light output is strong but slowly pulses down and gets very dim. Same with factory button. This looks like a common issue and warranty repairs sound like a gamble so are there any other reliable alternatives lights that use the 18650. My Scout issues have gone away...for now. Odd that you’re having trouble with clicky tail cap. Most issues I’ve read about involve a tape switch. To answer your question: Modlite |
|
|
|
Posted: 8/30/2020 8:13:15 PM EDT
[#34]
I was having issues with the old M961 dual switch and a brand new scout pro with clicky. last night I went out again after stretching the spring a bit at the end of last weeks shoot, and it seemed noticeably better this time. shitty to have to tweak a $400 flashlight to make it work for its intended role, but at least it was fairly easy. the spring came off when I pulled on it and it was kinda a bitch to get back on. I wonder if the spring on the modlight clicky is better.
|
|
|
|
Posted: 8/31/2020 5:54:07 AM EDT
[#35]
Quote HistoryQuoted: I was having issues with the old M961 dual switch and a brand new scout pro with clicky. last night I went out again after stretching the spring a bit at the end of last weeks shoot, and it seemed noticeably better this time. shitty to have to tweak a $400 flashlight to make it work for its intended role, but at least it was fairly easy. the spring came off when I pulled on it and it was kinda a bitch to get back on. I wonder if the spring on the modlight clicky is better. Oddly I too “pulled the spring”, short of removal, among other things. Maybe there is a benefit. |
|
|
|
Posted: 9/1/2020 8:45:32 PM EDT
[#36]
I’m having the same dimming issue with my M600DF, but today something completely different happened. About 10rnds into my second mag, I noticed my light was on. Hit the ST07 pad a couple times and it stayed on. Unscrewed and removed the tan pad cap from the body and the light still stayed on. I had to remove the Surefire battery to get it to turn off. Once I got home, I put the battery back in to see if it was still malfunctioning, but it seems to be back to working...
No clue how these are supposed to operate electrically, but I’ll be contacting Surefire in the AM. |
|
|
|
Posted: 9/23/2020 12:11:51 PM EDT
[#37]
Any updates on these issues?
|
|
|
|
Posted: 9/23/2020 12:19:31 PM EDT
[#38]
Quote HistoryQuoted: Any updates on these issues? SF sent me a return label. I should be able to get it dropped off at UPS tomorrow. They want to “look at” the dimming issue, but said the light staying on was a bad battery casing.... the SF battery came with the light and went from the package, to the charger, to installed and there is no visible damage. I’ll post again when they return my light. |
|
|
|
Posted: 10/3/2020 9:22:15 PM EDT
[#39]
Bump
|
|
|
|
Posted: 10/3/2020 9:30:44 PM EDT
[#40]
My recently purchased black M600DF functions normally.
|
|
|
|
Posted: 10/4/2020 7:18:26 AM EDT
[#41]
My 600df died after 30 rounds at the range. It took over a month of waiting for surefire to offer a replacement by supplying a 600u... I just took it bc I needed a work light. But honestly, the CS response time stunk as did the solution.
|
|
|
|
Posted: 10/4/2020 4:23:25 PM EDT
[#42]
So far so good on my two M600DFs... knock on wood. Bought them when the M600DF was first introduced. One on my Colt 901 (.308), one on my Benelli M4. Both have taken tons of recoil battering. Will definitely be following this topic regardless though. Wonder if QC has slipped or been relaxed since the initials runs.
|
|
|
|
Posted: 10/7/2020 2:40:10 PM EDT
[#43]
I’m experiencing the same issues with a m600df I purchased in July. Using the 18650 that came with the light, and sr07 tape switch. Flickering and going into low power mode. Will post an update once I make time to call surefire.
|
|
|
|
Posted: 10/15/2020 12:07:38 AM EDT
[#44]
Mines doing the same thing.
|
|
|
|
Posted: 10/15/2020 6:34:02 AM EDT
[#45]
Received a confirmation email that my light made it to SF yesterday. We’ll see what they say.
|
|
|
|
Posted: 10/17/2020 1:22:19 PM EDT
[#46]
Quote HistoryQuoted: I was having issues with the old M961 dual switch and a brand new scout pro with clicky. last night I went out again after stretching the spring a bit at the end of last weeks shoot, and it seemed noticeably better this time. shitty to have to tweak a $400 flashlight to make it work for its intended role, but at least it was fairly easy. the spring came off when I pulled on it and it was kinda a bitch to get back on. [color=#ff0000]I wonder if the spring on the modlight clicky is better. [/color] I'd say yes it it. have one modlite with a DS00 tailcap and another with a modlite clicky tailcap. the DS00 flickers on bolt drop, dryfire,,etc . It's just the faintest of dimming but aggravates me to no end. the other modlite with modlite clicky doesn't fade/dim no matter what I do so I assume the springs are stronger, diferent material etc. I'm honestly looking at the REIN for the sole reason they have the battery jack. not sure if I'll give up the modlite since it's really a surefire issue but it's certainly aggravating after spending hundred of dollars |
|
|
|
Posted: 10/17/2020 1:52:06 PM EDT
[#47]
Jesus. Is this happening with the 340C too? I just bought a Surefire 340C not long ago as I thought Surefire was supposed to be a good light. I guess I could have saved a few hundred dollars and bought a Streamlight. I'm really beginning to think the people who push more expensive products are just talking out their ass.
|
|
|
|
Posted: 10/22/2020 8:02:15 AM EDT
[#48]
Received return shipping notice. Should be back to me in a couple days. Hopefully the issues are taken care of, but there wasn’t anything mentioned in the notice that identified what the issue was.
I’ll post again after I get a chance to test. |
|
|
|
Posted: 10/29/2020 6:27:18 AM EDT
[#49]
Received my light Tuesday. I’m pretty sure it was my light body and head, but definitely not my cap and tape switch. I had sent in an FDE cap and the plug end of my switch had been rattle canned a few years back. What I received was new and I have no issue with that. Matching the color is fine, but doesn’t really matter to me. No clue on if it was the original battery, but it was nearly dead when it arrived.
Whatever they did, it works now. No dimming and seems to be the same output as the Clicky cap, maybe slightly less, but it could just be in my mind. All in all, it’s sucked to have to deal with warranty, but SF took care of it professionally and reasonably quick. |
|
|
|
Posted: 10/29/2020 11:23:27 AM EDT
[#50]
I'd have to agree with OP in regards to waiting on these lights. I bought an m600df a number of months back and had the same issue with the flickering of the light under recoil/dry fire. Also had an issue with the light being stuck on without being able to deactivate unless the bulb head is loosened. I don't know what the cause of the issues is with these dual fuel lights but there seem to be a lot of reports of them with the same problems so it's definitely not an isolated situation by any means.
In Surefire's defense they did send me a replacement 18650 battery for free which solved the issue of the light being stuck on but the flicker issue remained. I also happen to have an m600aa with ZERO problems whatsoever so maybe its just the 18650s having problems? |
|
|
Win a FREE Membership!
Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!
You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.
AR15.COM is the world's largest firearm community and is a gathering place for firearm enthusiasts of all types.
From hunters and military members, to competition shooters and general firearm enthusiasts, we welcome anyone who values and respects the way of the firearm.
Subscribe to our monthly Newsletter to receive firearm news, product discounts from your favorite Industry Partners, and more.
Copyright © 1996-2024 AR15.COM LLC. All Rights Reserved.
Any use of this content without express written consent is prohibited.
AR15.Com reserves the right to overwrite or replace any affiliate, commercial, or monetizable links, posted by users, with our own.
