Since the elevation steps on the adjustable fronts I use are not as fine as the click-stops on my rear sight, there still may be a little change in elevation that must be dialed into the rear sight going from 300 to 600 yards, but it's a lot less than in years past. The steps on my front sight are each 0.050 inch, whereas a "quarter-minute" rear sight moves about 0.002 inch per click.

This front sight (shown with extra mounting base) allows the author to establish a rear sight height that gives him the head position he wants, without compromising on elevation adjustment for different yard lines.

The service rifle shooter, assuming he's using an AR-15, can't make such front sight elevation changes going from one yard line to the next, but he can use the front sight elevation adjustment to help establish his no-wind zero. Some service rifle modifications allow for wind adjustment in the front sight, but this is also only exploited during initial zeroing efforts. From that point, all elevation and wind adjustments must be done at the rear sight.

Of primary importance to the .223 Remington shooter is retaining as much upward elevation adjustment as possible, and this means that it's wise to establish an elevation zero for 300 yards that maintains a minimum but adequate amount of downward travel to get on target center for the 200-yard events.

The event zeros for standing and rapid-fire sitting are considerably different due to elements introduced by my shooting position preferences, but they are still recorded as changes from my 300-yard no-wind sight setting.

After establishing the no-wind zero (remember, it's for the 300-yard rapid-fire prone event), the other event zeros are likewise a matter of firing the event and settling on an index that produces a centered group in ideal shooting conditions. The zeros should then be recorded in your data book or, in my case, written on a strip of tape affixed to the rifle's stock tube.

To me, ideal or excellent conditions mean, primarily, the absence of wind. Good lighting conditions and moderate temperature are others. Essentially, no extremes. Trying to establish a zero on a day with even a light breeze is counterproductive. I'm usually working with my loads and have them going through a new barrel early in the spring, prior to the start of the shooting season. This is when I establish zero, and it's a matter of patience and timing to catch a day where I know zero will be accurate.

The wind will blow, the sun will glare, clouds and rain will come up, and it's going to get hotter and colder too. Along with these condition changes, the day's sight setting that will clean a target will also change. Having a place to start, though, is the only way to know which direction to head when faced with these changes. You will find also that having a place to start is sometimes most important because it also gives you a place to return to.