My BTU weight exactly 1200g loaded. FYI. 
Edit:
For comparison, my SRK weighs 492g loaded.
Also, the UF-T90, 1040g loaded (3x26650).
The BTU is my heaviest light so far.
Are these good springs for the battery carrier upgrade mod?
http://www.fancyflashlights.com/goods.php?id=140
My stock BTU tested at 2880 at 30sec on turbo, 2160 on high, 928 medium, 68 low.
Now with xml2’s on copper - 3670 at sec on turbo, 2520 high, 1025 medium, 75 low.
So even high is very respectable. I never tested throw on different levels, but I’d be willing to bet its still 100k or more on high.
And both tests done with 3400mah protected Keeppowers. And this is the BTU driver.
Is PWM bad with the BTU driver?
I think these are ones I used on one Shocker - really stiffens them up if your not into the soft stock ones. IOS has pretty much the same ones, believe sold as the "A" size. I got them both - went nuts buying any/all springs... If you copper braid the springs though, not sure you really need them.
Down to 11 in stock, really has me think'n.....
Joe - think I read recently the BTU stock driver is not using PWM's at all, but regulated in all modes. The DRY driver does use PWM, and I think poorly -- read this in a BTU thread, not sure where now...
I am real sensitive to PWM and it is not at all visible.I have the BTU driver,not the dry.
How far from your metter when you did that test?
For throw - I’ve done 5m, 10m, 15m, & 25m tests. All about the same results - about 125k stock, 181K with the XML2’s and UCL lens. I have not tried it just high yet though. But a stock high with 2160 lumens it still should be respectable.
What does your meter say for the BTU stock at 1 meter? Did you check it there?
So many questions 
Springs on the holder are fine, I added copper braid, but didn’t help much.
I didn’t detect any PWM on the BTU driver (which is now dead), On the DRY driver I cannot see it, but I can hear it in all modes (even Turbo) if I point the light at a black piece of paper. Seriously, sheer the intensity of the light makes a noise when it hits a dark piece of paper. Crazy bright.
My particular unit tests relatively low, and I think there may be something wrong with my light. Everyone else seems to have no problems, so it may be a one-off.
There have been a lot of BTUs sold today. I think they will be gone by tomorrow.
Just wondering what XM-L2’s on copper you used? The only ones I can find are from LED-tech.de and are pretty expensive, about $60 for 3 delivered!
Truthfully, I don’t know. I’ve tried several other lights that throw over 100k at 1m, and everyone reads off, many way off. SR90, TN31, tn31mb, Deerelight, etc. If I light is a serious thrower, I just start them at 5m. My TN31mb (426k) and SR90 w/ sbt70 (325k), even reads off a little at 5m. But not too far off. At 10m the read proper. And by proper I mean the same consistant numbers from 10m - 100m.
From all my testing, this is the way I see it as best minimum testing distances -
0-50k - 1m test
50-100k - 3m test
100-200k - 5m test
200k & up - 10m test.
Any one have a NW Shocker?
No problem.
Your getting quite the collection there.
According to the website the BTU weighs 1200grams without batteries. That’s 2.6lbs roughly.
Specification:
◎3* Cree XM-L LED (U2) CW / CREE XM-L T6 3C NW with a lifespan of 50,000 hours
◎Battery: 3 x 18650
◎204 mm (length) x 52 mm(body width) x106 mm(head diameter)
◎1200-gram weight (excluding batteries)
Bare emitters reflowed onto 20mm SinkPAD's - I do it in a frying pan 
, works pretty well, did dozens, check temp with a temp meter. They were XM-L2 U2's 1A or 1C's, forgot which. IlluminationSupply is a great source for the 1C's, but they might have been from Mouser.
Quit thinking about it and just buy it!
Tom E, they were XM-L U2 1C from IS. A great thrower tint, IMO. I did virtually the same mod.
It’s not hard to do, but I would not recommend it be your first mod. Try something smaller first.