Maybe a stupid question, but for those of you that have mounted your light to a standard rail, is the light supposed to be able to move to its four notches, or should that stop once you tighten the cross bolt since that should also clamp it to the rail?

Mine still can move when I tighten it down. It's secure in the lug, but the light unit can still slide along the rail back and forth 4 clicks.

The instructions say tighten "until the FOXTROT1X is secured onto the rail and cannot be moved forward or back." It also says to push forward on it while tightening, which seems this would take it out of whatever position you want it to stay in when you tighten it, if it's not supposed to move.

Or, maybe I have a skinny 1913 rail on this pistol.

Thanks