More times then not it is a combination of recoil indused muzzle climb and the fact the majority of handguns have a right twist and eject right, so you deal w/ more forces as the hangun becomes lighter. Many shooters fight the twisting of the handgun taking the shots high right. If you change your grip to support the left side more, it will dissapear. I had this issue w/ a Wilson Commander in .45acp. I changed the grips to Hogue wrap around w/ finger grooves and it all dissapeared.