Has anybody mounted a Streamlight Thunder Ranch TL2 light on a rail on their AR-15? I'm curious to what kind of flashlight mount (First Samco, etc...) anyone used. Appreciate it.

BOTACH(clearing throat sound, spit hits floor) sells a very well made mount which fits the unique Streamlight body diameter.  I've run a TL-3 LED (rated 90 lumens) several hours of range time in pretty hot conditions without failure.

The Thunder Ranch kit comes with a TL-2 LED IIRC, rated maybe 30 lumens, but the hot spot is nice.  For indoor use it (TL-2 LED) is surprisingly effective, and is a very compact lighting arrangement.  As an aside, the Streamlight 3AA tasklight rated a similar 35 lumens is my favorite everynight flashlight and runs something like 20 hours.  The 3AA body has enough length to aid its impact weapon ability.

I have a TL-2 LED in my survival knife sheath pocket, and another in my handgun travel kit.  A third sits next to a TL-3 (rated 200 lumens) on my book shelf close at hand.  They are not hard on batteries, drawing less than 500mA(actual 400 to 470 mA).

Compared to other "tac" lights the TL-2 LED is not very bright on paper, but that is one of its advantages as it reduces the deteriorated night vision that happens when lighting a room with 200 lumens.  You lose some offensive blinding ability with the TL-2 LED, but preserve your own vision better.  HTH.

Paladin