This is the light that I have on my Sport 2:
This is the mount that I use, as the diameter of the flashlight is a little bigger than 1":
Both have held up very well through numerous magazines (probably not as many as most here would like) with no cut-offs and have not come loose. My AR will most likely sit in the safe until either the SHTF or I just feel like shooting it at the range, so the need for a $100 plus light just was not an issue. However, after using and abusing this light for a few years now (not always on a gun), I would have no qualms about using it in a defense situation.
It is definitely worth a look...
****NOTE: Apparently you have to click the lower Amazon link to view it...