- 01: Introduction
- 02: History
- 03: Propellants, Firearms, and Ammunition Development
- 04: Modern Firearms Manufacture
- 05: Small Arms Ammunition
- 06: Evidence Handling Procedures
- 07: Equipment and Instrumentation
- 08: Examination of Firearms
- 09: Cartridge and Shotshell Examination
- 10: Characterization and Evaluation of Fired Projectiles
- 11: Bullet Comparison and Identification
- 12: Gunshot Residue and Distance Determination
- 13: Toolmark Identification
- 14: Communicating Results
- Resources
U.S. Department of Justice, Office of Justice ProgramsNational Institute of JusticeThe Research, Development, and Evaluation Agency of the U.S. Department of Justice
Equipment
Home > Characterization and Evaluation of Fired Projectiles > General Riflling Characteristics > Equipment
Using a comparison or stereomicroscope, land and groove impressions can be measured using a variety of equipment:
- Micrometer
- Calipers
- Glass measuring reticule
- Electronic reticule
- Digital measuring equipment and software
- MP 6 optical projector (no microscope)
- Machinist’s scale
Descriptions of each of the above equipment can be found in Module 7.
A technique used by many examiners for measuring the widths of land and groove impressions is the air gap method. This technique is fast and accurate, requiring only a calibrated microscope and a micrometer. Calipers can be substituted for the micrometer.
