I've had a TA-01NSN for a couple of years now but hadn't used it much.  I just put it on a Larue mount and had it out to zero this morning when I noticed something funny.  There were times that I could discern the crosshairs, stadia lines and range numbers clearly and just as often, especially after a mag reload, they would be fuzzy and indistinct.  I tried changing focus from background to foreground, cleaning the lenses and 'looking off' but nothing but apparantly time seemed to help.

What gives?  I could still use the primary crosshairs well enough but the stadia lines were a lost cause when this happened.  Any ideas?  Thanks!

The crosshairs are parallax free along the vertical axis.  They are infocus when you are focused at that distance that they correspond to.  You must look at them while the background is thet distance.  If you just tryt to look directly at them they will appear out of focus.  Additionally the side of the crosshair due to this method of creating differential focus causes the crosshair off the to edge of the scope to become focused beyond infinity and will always appear blurry.