Fighter Combat - Tactics and Maneuvering

10 FIGHTER WEAPONS
the ballistics of tracer ammunition generally varies slightly from the
ballistics of the nontracer rounds, the trajectories also are likely to differ
slightly, which can be misleading, especially when the pilot is firing at
long range. Difficulties in depth perception can also make assessment of
tracer trajectories ambiguous. With the advent of effective air-to-air gunsights,
the disadvantages of tracers in combat probably began to outweigh
the benefits.
[The commanding officer] ordered the tracer ammo removed . . . I'll never
forget the spectacular results we got. Our kill rate went up from 50 to 100 per
cent.
Colonel Charles W. King, USAF
5 Victories, WW-II
In the absence of an ammo-remaining indicator, tracers have been used
to warn the pilot that his ammo is nearly spent. For this purpose, the last
few rounds in the can might include some tracers. It doesn't take long for
an observant enemy to pick up on this practice, however, and it may give
him the advantage of knowing which fighters are low on ammo. Some
other indicator of rounds remaining is, therefore, preferable.
Aii-to-Aii Gunsights
The earliest sights for air-to-air guns were of the fixed variety, most often
consisting of a ring and bead, as illustrated in Figure 1-2. This arrangement
usually included a ring or concentric rings with cross-braces located near
the muzzle of the gun, and a vertical post located near the rear of the gun,
closer to the pilot. (Sometimes these positions are reversed.) By moving his
head so as to align the tip of the post (the bead) with the center of the ring,
the pilot was sighting down the GBL. Since the size of the ring was known,
as was generally the size of the target (wingspan is the most common
measure used for target size), the relationship between the ring and the
apparent target size varied with target range. This relationship provided a
handy range-estimation method. For instance, the pilot might know that
he was within the maximum effective range of his guns when the wing-
Figure 1-2. Ring-and-Bead
Sight