Folks have been using spirit levels on front sights for decades. Once calibrated for how much angle the rifle cants for a given shift of the bubble to one side, it's easy to correct for wind.
US Navy Distinguished Marksman Badge 153
Former USA Palma Team Member
NRA High Power Long Range High Master
NRA Smallbore Prone Master
Last edited by Bart B.; July 13, 2013 at 05:33 AM.