You can use the front sight on an open sight rifle to estimate how much of the front sight covers the target. To do this you need an assistant to measure the distance from your front sight to your eye when the weapon is mounted and you are in your firing position. Assuming that the distance is 30 inches then multiply 30 times .0003 (actually .000291) and divide by the width of the front sight. The answer is the area in inches covered by the sight at 100 yards.

This is essential information to the iron sight hunter. When I was a kid reading Francis Sell I had quite a bit of difficulty understanding bead size and how it covered game.
As I learned more about math and gained experience hunting small game I began to understand what the “old timers” were talking about.
Using negative trajectory sighting the old guys good use a six o’clock hold for short range, hold dead on for medium range and a higher hold for long range.
The “fine art” of iron sight shooting must be continually practiced – it’s helps that its fun.

Thanks for the kind words. The only thing I would say about this is to be careful about adjusting point of aim on uphill and downhill shots. As it turns out, in both cases it is necessary to aim low to hit the target. This is contrary to folklore and common practice but is correct.....aim low uphill or downhill...

Yes. The horizontal distance to the target is reduced in either the uphill or downhill case, and the pull of gravity perpendicular to your line of sight, which is what pulls the bullet off of it, is proportional to that horizontal distance. As you might imagine, firing straight up or down, the horizontal distance covered is zero (not counting earth rotation and wind effecta) and there is no gravitational pull that tries to move the bullet off your line of sight at all. So, any elevation of the muzzle off horizontal is part of the way toward that vertical case, having less drop rather than more.

When I took Gunsite's 270 class we were instructed in the front post range estimation system, and it worked very well. My M1A battle sights let me stay in the 8" circle with it to the 400 yard maximum range the class employed. We had the luxury of seeing full size targets at known ranges for feedback, though, and of shooting at them to validated the estimate. There is, however, no need to set them up at actual ranges just to see how they would appear in the sight picture. That can be done with reduced target profiles at 100 yards. You just need a distance long enough for normal focus blurring to occur as you shift between the target and front sight in checking your range estimate. If you put up a one third-size and a one quarter-size deer or elk silhouette at 100 yards, you will see how a full size version of the target would look relative to your front sight at 300 and 400 yards. This also lets someone using an optical sight see where any reticule graduations or other special geometry it may have will appear with respect to such silhouettes.

Good comments...the other thing that happens in complex terrain is range estimation error when the uphill or downhill slant angle is significant. The classic example is where observed range to the target is 335 yards on a downhill slope of 45 degrees. The real range is 236 yards..now.....given the folklore notion that shooting uphill requires an elevated sight picture and you have a clean miss.

45Cos * 335= 236 yards

A good teacher for the downhill side of this discussion is bow-fishing. Defraction of light when looking at fish from an angle through water. NOT the same. Just a teacher.

Cheezywan