Which part is NOT part of the M115 Bore Sight?

The M115 Bore Sight is a tool used to align the weapon system accurately for improved targeting and accuracy. It consists of several components that aid in its operation. Among these components, the plunger, cross level vial, and elevation vial are critical for ensuring the correct alignment and leveling of the sight.

The cross level vial helps to level the bore sight horizontally, while the elevation vial assists in leveling it vertically, allowing for precise adjustments. The plunger is used for securing the bore sight in place within the weapon's bore, ensuring stability during the alignment process.

In contrast, the safety wire is not a functional part of the bore sight itself; rather, it serves a collateral purpose for safety during the usage of the bore sight. It is likely included to prevent accidental removal or displacement of the bore sight during operation, but it does not contribute directly to the core functionality that aids in aiming or aligning the weapon.

Thus, identifying the safety wire as the part that is not integral to the M115 Bore Sight’s primary operational capabilities clarifies its role versus those of the other components.