It seems that I'm perpetually exploring the best way to mount a PentagonLight X3 on an M4-gery equipped with a rail fore-end.  

I've been giving a lot of thought to mounts by La Rue and Daniel Defense, but they seem to be optimized for use with a vertical foregrip, and accordingly they tend to stick out a bit from the rail so that you can actuate the light with your thumb from the vertical foregrip.

What I want to be able to do is mount the light forward on the left side of the fore-end, as close (low) to the fore-end as possible on the left side of the rifle so that I have the option of actuating the light with either my thumb (tail cap switch) or my fingers (tape switch).  

I'd be very open to hearing about what types of rings/mounts fit this requirement.  I'm open to any suggestions, brands, mounting types (allen head, throw lever, thumb screw, etc.).

I thank the collective in advance for the wisdom lurking out there!

Thanks again,

Adam

http://ar15.com/forums/topic.html?b=3&f=20&t=180898&page=12

go to the link look at the second picture in the threat posted by DYFFY this may be what you are looking for. I know it is a surefire mount I just don't know what it is called.

+1 to the Viking Tactics mount.