Detection, Inspection, and Enforcement
6. Weapon Performance Characterization
The ability to characterize the performance of a weapon is useful to understand how to develop and characterize countermeasures, such as ballistic armor for small arms weapons.
6.1 Ballistic Chronography
Goals
To develop a reference ballistic chronograph by which other chronographs can be calibrated and develop an associated measurement uncertainty analysis.

Figure 23. Diagram of ballistic chronograph.

Figure 24. Head of ballistic chronograph. The green section attaches to the barrel of the weapon. The bullet is output from the opposite end of the head after breaking three laser beams.
Customer Needs
The evaluation of the performance of body armor requires knowledge of bullet speeds. For manufacturers to accurately and reproducibly assess the performance of their products, the speed of the bullet must be known accurately.

Figure 25. Data from ballistic chronograph. The three pulses each correspond to the bullet passing through one of the laser beams. The known distance between the beams divided by the time (see figure) it takes a bullet to travel between beams gives the speed of the bullet.
Technical Strategy
Complete the calibration methods for the reference ballistic chronograph and determine its measurement limitations.
Deliverables
A summary report describing the performance of the chronograph.