I've got an angle adapter on one of my ARs to mount a Surefire G2 flashlight. The AR has a Leopold 1x3 scope, which has a short section of Picatinny rail on top, and the adapter puts the light off to the side enough to make scope adjustments accessible. I think I got the angle adapter from YHM. Yankee Hill Machine. Sorry, don't have the URL. You'll have to googlit.