- 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
Hand Fitting
Home > Modern Firearms Manufacture > Fine Forming Operations > Hand Fitting
Gap between cylinder and breechface
Depending on the design of the firearm, some parts may need individual adjustment to properly fit with other parts. Hand fitting is an extension of fine-forming operations and usually requires filing, stoning (fine grinding with a hand tool), and pressure fitting the parts.
The firearm examiner may encounter hand-fit surfaces when examining breechface markings produced by revolvers. After the manufacturer fits the cylinder to the revolver, the gap between the cylinder and breechface may require adjustment by filing. Filing is an operation that cannot be performed the same way twice. Chips in the file produce random marks, and the file wears a little with every pass. This results in a distinctive pattern of microscopic marks.
