a, b, c--open sight
d--peep sight
The sighting drills will visually illustrate the following kinds of sights.
a--Normal Sight. This is the sight most frequently used. The following illustration is the normal sight when the open sight notch is used.
The figure i-k-l-m is the front sight B-L-M-C the rear sight notch.
When the open sight is used the above diagram shows the correct alignments of the rear sight notch, front sight and the bull's-eye. The following features should be noticed:
1st. The front.sight (i-k-l-m) is exactly in the center of the rear sight notch (B-L-M-C), if it is in the right or left part of this notch the rifle will shoot to the right or left of the point aimed at.
2d. There is a thin strip of white seen between the top of the front sight and the bull's-eye. (The Marine Corps and many army officers do not see this strip of white. The method of aiming given and illustrated in this book is the same as found in the Firing Regulations for the Army.)
3d. The top of the front sight should just touch an imaginary line connecting the shoulder at C with that at B. (This is most important.)