The 12 gauge roll crimp is a popular choice for shotgun shell reloaders, offering a reliable and consistent method for securing the shot and wad within the shell casing. This guide will delve into the intricacies of the 12 gauge roll crimp, covering everything from the mechanics of the crimp to troubleshooting common issues. Whether you're a seasoned reloader or just starting out, understanding the roll crimp is crucial for producing safe and effective ammunition.
Understanding the Roll Crimp Mechanism
The roll crimp works by using a set of rollers within the reloading press to gradually compress the shell's mouth, creating a secure seal around the wad. Unlike other crimp styles, the roll crimp doesn't involve a sharp, sudden deformation of the metal. This gradual compression leads to a more consistent and reliable crimp, minimizing the risk of misfires or inconsistent shot patterns.
Advantages of the 12 Gauge Roll Crimp:
- Consistent Crimp: The rolling action creates a uniform crimp, ensuring a reliable seal and preventing shot leakage.
- Reduced Damage: The gentle pressure minimizes the risk of damaging the shell casing, extending its lifespan.
- Versatile: Suitable for various shot sizes and wad types.
- Relatively Easy to Master: With proper setup and technique, achieving a consistent roll crimp is relatively straightforward.
Disadvantages of the 12 Gauge Roll Crimp:
- Requires Specialized Equipment: You need a reloading press equipped for roll crimping.
- Sensitive to Setup: Proper adjustment of the crimp die is crucial for consistent results. Incorrect setup can lead to under- or over-crimping.
- Potential for Over-Crimping: Applying excessive pressure can damage the shell casing.
Setting Up Your Roll Crimp Die
Achieving a perfect 12 gauge roll crimp relies heavily on the proper setup of your reloading press and crimp die. This involves several key steps:
1. Shell Plate Adjustment:
Ensure your shell plate aligns correctly with the die. Improper alignment can lead to uneven crimps and shell damage.
2. Crimp Starter Adjustment:
The crimp starter, if your die has one, initiates the rolling process. Adjust it to lightly start the crimp without deforming the shell's mouth too aggressively.
3. Crimp Groove Adjustment:
The depth of the crimp groove determines the final crimp height. This adjustment requires careful attention to detail, and often involves several test runs and adjustments to achieve the ideal crimp.
Troubleshooting Common Roll Crimp Issues
Even with careful setup, you might encounter some problems. Here are some common issues and how to address them:
Over-Crimping:
This leads to deformed shells and potential damage to the firearm. Reduce the crimp die's adjustment.
Under-Crimping:
This leaves the shot and wad insecure, leading to potential shot leakage or inconsistent patterns. Increase the crimp die's adjustment.
Uneven Crimp:
This points to improper shell plate alignment or a poorly seated wad. Double check alignment and wad seating.
Conclusion
Mastering the 12 gauge roll crimp is a key skill for any serious shotgun reloader. Understanding the mechanics, setting up your die correctly, and troubleshooting potential problems will ensure you produce safe, reliable, and accurate ammunition. Remember that safety is paramount; always consult your reloading manuals and follow best practices. Consistent practice and attention to detail are the keys to success.
