Contrary to conventional wisdom I run a Surefire X300 on the left side.
-I tried running it way out on front. (I don't like holding my arms out the "new cool" Costa way of running a rifle.
-I tried running it on the outboard side, the way everyone says it is supposed to be run. I would miss the light switch sometimes and the shadow of the barrel obscured a large portion of my light.
-Running it on the left side (inboard for me), allowed me to hit the light with my thumb, and the barrel shadow winds up on my right side, which is partially obstructed by the housing of Aimpoint anyway so the light isn't as important to me on that side as it is on my unobstructed left side.
My big decision maker was back a while ago. I own 200 acres of woods back home and I noticed that there was a trail in a location that I didn't make. It was starting to get dark but I wanted to check it out, so I grabbed my rifle and some spare mags and walked the trail. (Meth cookers are rampant in my home county)
While walking down the trail as dusk was settling in, I heard a rustle off to my right side, so I spun and tried to illuminate the noise in the darkness under the trees. I fumbled the light REALLY bad. (Mounted to the Outboard side). It turned out to be a rabbit, but missing that light really smacked me hard. I also noticed and didn't like how much the barrel shadow obscured what I was actually seeing. It didn't seem that bad in the house with bright taupe walls. Outside, at dusk with trees, a lot of the light was absorbed rather than being reflected back at me and making it look brighter. So I swapped sides right then and there.
The other added benefit for me is that if I were to ever need to shoot around the corner from my bedroom down the hall into my living room and need to illuminate a target, it is a left hand corner, so I would probably be blinding myself if I used the light on the right hand side of the rifle.
I am NOT a tactical expert though. Just a guy who likes evil black rifles and actually uses them occasionally.
