The last is the “ghost in a ghost” sight. The front sight is a ghost ring with a post in the middle. The rear sight is a ghost ring, allowing the two circles to be superimposed. These sights are very easy for the eye to pick up, especially when needed quickly. The version made popular by Heckler & Koch on their MP5 remains my personal favorite for CQB. A set of different-sized “diopters” at the rear allows you to adjust for various ranges as well as the distance between your eye and the front sight.
Without regard to type, the front sight determines your point of aim. The rear sight is a reference point for your front sight. On shoulder-fired weapons, the rear sight is seldom in focus and should not be. The bullet follows the front sight; the rear sight simply assists in that process. As a rule, the more “in focus” your front sight is, the more precise your accuracy. Whether a post, dot, bead or blade, it is all about placing your front sight on the target and keeping it there until the firing process is complete.
Circles & Ghosts
Aperture rear sights use some sort of open circle or hole. The diameter of the opening determines how precise you can be. The bigger the hole, the faster it is to find the front sight. Smaller holes allow for greater precision. In many cases, the sight will have two different sizes: One for close work and one for longer ranges.
Blade sights can also have narrower or wider notches. The larger the notch, the quicker that front sight can be found. Narrow notches allow for some excellent precision. Solid accuracy is possible if you line the front sight up against the top of the rear sight and make certain the post is in the middle.
The HK diopter sight is really two ghost rings with a post. The front has a circular sight that contains a post. The rear has a series of ghost rings of varying sizes. For CQB work, you use the largest hole (diopter). When the “shadow” between the front and rear “ghosts” is equal, you have center mass. It is incredibly fast. If you need precision, you use the post for a more precise aiming point. For even more precision at longer ranges, you change to a smaller hole.
Always on Target
In many cases, the smaller rear holes in these sights are designed to compensate for bullet drop. If you use a smaller hole up close, it may change your point of impact.
Initial zeroing is the most important time spent setting up your rifle. Properly zeroed, iron sights are excellent. Fail to start with a proper zero and it can be incredibly frustrating. By taking the time to properly zero your iron sights, you will ensure that you are accurate and precise in combat.