What is Roll Crimping?
Roll crimping is a traditional method of closing shotshell cases that creates a secure, rounded closure at the end of the shell. Unlike star crimps that fold the hull into a star pattern, roll crimps use a cylindrical crimp that rolls the hull edge over a top wad or card, creating a smooth, rounded finish.
History and Applications
Roll crimping has been used for over a century and remains popular for specific applications. It's particularly favored for:
- Buckshot loads where consistent patterns are critical
- Slug loads requiring maximum accuracy
- Vintage shotshell reproduction
- Specialty loads with specific performance requirements
Advantages of Roll Crimping
Roll crimps offer several distinct advantages:
- Consistent performance: The uniform closure provides reliable ignition and consistent pressure curves
- Better for hard projectiles: Ideal for buckshot and slugs that don't compress like shot
- Reduced deformation: Less stress on the projectiles during crimping
- Traditional aesthetics: Classic appearance valued by collectors and traditionalists
The Roll Crimping Process
Creating a proper roll crimp requires precision equipment and careful technique:
- Load components according to your tested recipe
- Place an over-shot card or top wad
- Use a roll crimping tool to gradually form the crimp
- Apply consistent pressure to create a uniform roll
- Finish with a crimp finisher for a factory-quality appearance
Equipment Considerations
Quality roll crimping requires specialized tools designed for precision. Premium crimp finishers ensure consistent, professional results with proper hull support and controlled pressure application. The right equipment makes the difference between amateur and factory-quality crimps.
Common Challenges and Solutions
Reloaders may encounter several challenges when roll crimping:
- Uneven crimps: Ensure consistent hull length and proper tool adjustment
- Split hulls: Avoid over-crimping and inspect hulls for wear
- Loose crimps: Verify proper component height and crimp depth
- Inconsistent appearance: Use quality crimp finishing tools for uniform results
Roll Crimp vs. Star Crimp
While star crimps are more common in modern reloading, roll crimps excel in specific applications. Star crimps are faster and work well with shot loads, while roll crimps provide superior performance for slugs and buckshot where consistent, hard closures are essential.
Conclusion
Roll crimping remains a valuable technique for serious reloaders seeking maximum performance from slug and buckshot loads. With proper equipment and technique, you can achieve factory-quality results that deliver consistent, reliable performance in the field.