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Firearms Examiner Training

Finishing

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Finishing

Finished cast bullet with cannelure
Finished cast bullet with cannelure
National Institute of Justice (NIJ) (see reuse policy).
National Institute of Justice (NIJ) (see reuse policy).

At this stage, bullets are usable but some may require processing to add other features. The most common is the crimping groove or cannelure, which may be functional or cosmetic in nature. This can be accomplished on the bullet assembly press or at a separate work station.

At this point, the bullets are covered in processing oils and need to be cleaned. These oils are removed by washing or dry tumbling in clean, ground corn cob. Cob is absorbent and provides the additional benefit of giving the bullets an attractive polishing.

Bullets need to be tested prior to distribution and sale. Sample bullets for each lot are inspected for dimensional compliance and accuracy.

 

Cartridge Case Manufacture

Cartridge cases fall into two broad categories -- metallic and shotshell. Metallic cartridges are used in rifles and handguns and are comprised completely of metal. Shotshell cases are most often hybrids, combining a small amount of metal with paper or plastic.

Metallic Cases

Metallic case production is similar to bullet jacket production, except that the raw material is brass (copper: zinc ratio of 70:30). In brass mills, the standard name for this alloy is cartridge brass. Rimfire and centerfire cases require different processing.

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