On an icy Colorado morning in February, we repaired to a low-lying ridge with a sagging picnic table and a sheet of plywood to sight in the rifles. The guide wore buckskins. My head was covered in coyote fur. Our quarry was a renegade bison wandering the sagebrush hills with a band of young admirers. It was not the 1880s, but we were trying to make it so with a replica Winchester High Wall made by Uberti (and very nicely made, too) in .45-90.

Its factory sights were a simple front blade and open rear sight of the buckhorn persuasion. The rear sight was adjustable for windage by sliding it right to left in its dovetail and tightening a tiny set screw. For elevation, it had the usual movable blade in a slot, with steps of varying heights, held in place by the spring pressure of the sight itself.

These should be the most foolproof of all iron sights--simple to a fault and crude to adjust but immovable and fast as lightning. Two problems: As budding mountain men, we did not have among us an optometrist’s screwdriver for the minuscule set screw, and the knife blade didn’t work.

As for elevation, the movable blade moved all too easily. The steps were level, rather than shallow Vs that lock in place, so every time we fired the rifle the recoil moved the blade back to its lowest setting. With a .45-90, that moved the point of impact about a foot at 100 yards. Try remembering all that when you are belly down in the snow, peeking at a bison 50 yards away through the grass, with him staring back.

This scenario highlights some of the problems and advantages of hunting-style iron sights. In an age of superb optical sights, unless one is using them purely for nostalgia, iron sights should offer some real advantages in the field. Otherwise, why bother?

What are these advantages? First, they can (and should) be simple, rugged and unobtrusive. Second, they should be easy to adjust but not eager to get out of adjustment (the biggest knock on target-type iron sights). Third, they should neither interfere with the operation of the rifle nor get in the way.

On big game out to 100 yards, no system is better than the basic blade or bead combined with an open sight on the barrel. The sight adjustments may be crude and awkward, but once they’re aligned they work. At these ranges, you will likely be shooting quickly at an alert animal, and speed will be more important than pinpoint accuracy.

From 100 to 300 yards, which is stretching the practical limit for iron sights on a big game rifle, a receiver or tang sight with an aperture is more exact. At these ranges, you have time to settle in and aim.

One place you see iron sights in common use is on a double rifle or bolt action for dangerous game. Open sights are standard, often with a quarter-rib and a selection of folding blades (the “express” sight).

These arrangements are great in theory, offering settings out to several hundred yards, but in practice they may not be so good. Recoil can cause a raised blade to flip back down, and remembering to check this in the heat of the moment is a bit much to expect (much like the moving elevation blade on the High Wall mentioned above). Most hunters who buy rifles with express sights don’t shoot them enough with the blade raised to see if this is a problem.