Possibly a different setup. Bare emitter readings can be different from reading it through an optic or reflector.
I assume you tested with optic/reflector since bare emitter is always rosier.
Yeah. Tool AA with some dcfix. I wouldn’t say it’s super scientific. Just a general idea of the CCT and where it is broadly on the BBL.
Got some sw45k’s in the mail today, super fast shipping to TX. Put one in my titanium Tool AA:
Here’s the sw45k:
And the 219B 4000K d200 that it replaced:
Fun stuff! Thanks azhu! 
Why didn’t you like the sw40? It looks less magenta. Where did you buy that sw40?
I liked it just fine, I just wanted to see what the sw45k looked like in this light. That sw40 was from Illumn.
Put one of the sw45k’s in my Streamlight ProTac 2L-X for fun. I had an LH351D in there which I think I prefer for the larger hot spot and brighter beam. However, it’s kind of a pain to solder the leads back on once the star is seated, so this will probably stay for a bit before I swap it back.
Tool AA 2.0 sw45k:
Streamlight ProTac 2L-X sw45k:
That’s a lot of equipment!
That’s not even a fraction of it lol. It’s a playground, and where I cut my teeth on more involved electronics repair. One of the perks is having a great place to tinker on my own stuff such as flashlight mods. 
I went ahead and put the LH351D back in the streamlight; it was worth seeing what it was like, but I’d rather use these 219B’s on other lights.
UPDATE: sw35 and sw45k are now back in stock. sw30 is still low.
j_mcsquare swapped some of my emitters into his LT1 and results compared to stock are pretty nice. Thanks Jack!
Link to images are here on imgur
I would like,
8 sw30
8 sw35
3 sw45k
please and thank you.
PM
TTT
If you’re on lockdown and want to learn to reflow your own emitters, now is the time 
3 x sw30
7 x sw45k please
Nice pic! PM sent.
I’m locked down in a different place than the hot air station 
Bummer… so no flashlight mods till this whole covid-19 fiasco is over?
I can do some stuff with a soldering iron, but anything that needs hot air or a microscope will have to wait. It’s OK, family and work keep me super busy still even stuck at home. I’m grateful I can still work!