When you're writing a novel it is not a bad idea to know about and tell the readers the name of the instrument that your character is using.
"Tom eased Maulin’ Molly around to come behind the jagdpanzer. He set the K-14a gun-sight for rockets. "
P-51 Mustang cockpit w/K-14a gunsight
K-14a Aerial Gunsight
The K-14 gyroscope gunsight automatically gives the correct lead. Though complicated internally, the sight is easy to operate with a little practice.
The K-14 contains 2 sights: The computing, or compensating sight and an ordinary fixed electrical sight. In the fixed sight, a cross has been substituted for the pipper. The fixed sight can be used alone.
The gyro sight consists of a dot surrounded by six small diamonds. The dot is centered on a target by maneuvering and keep the target properly surrounded by the six diamonds until the desired effect is achieved.