- 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
Digital Equipment
Home > Characterization and Evaluation of Fired Projectiles > General Riflling Characteristics > Equipment > Digital Equipment
MP 6 optical projector
MP 6 Optical Projector
The process for measuring land and groove impressions with an optical projector is as follows:
- Mount the nose of a bullet on a moveable stage - the bullet image is projected onto a hooded screen that displays a measuring grid.
- Bring both edges of the selected land or groove impression into focus.
- Align one reference point on the impression with a line on the measuring grid - the reference point is designated as zero.
- Move the bullet and its mount by rotating the knob until the next reference point is reached – the width of the land or groove impression is displayed in an LED readout in thousandths of an inch.
- Rotate the bullet on its mount to the next land or groove impression.
- Repeat steps 2 – 5 until all land and groove impressions are measured.
