Lee Precision's powder measures are popular among reloaders for their affordability and reliability. However, mastering their use requires understanding the Lee powder measure chart and its implications for accurate reloading. This comprehensive guide will delve into the intricacies of the Lee powder measure chart, helping you achieve consistent and safe powder charges for your ammunition. We'll cover everything from understanding the chart itself to troubleshooting common issues and ensuring accurate powder dispensing.
Understanding the Lee Powder Measure Chart
The Lee powder measure chart is crucial for setting up your powder measure correctly. This chart isn't a single document; rather, it's a system of charts and instructions that vary slightly depending on the specific Lee powder measure model you own. Generally, these charts correlate the measure's adjustment settings with the approximate powder charge weight in grains. Understanding this correlation is vital for safe and accurate reloading.
Deciphering the Chart's Information
The charts typically provide information organized by:
- Powder Type: Each powder type (e.g., IMR 4895, Unique, etc.) behaves differently, impacting the throw weight. The chart accounts for these differences.
- Charge Weight: The desired powder charge weight in grains is listed. This is your target.
- Measure Setting: This is the crucial information—the specific adjustment setting on your Lee powder measure (often expressed as a number or a combination of numbers and letters) needed to achieve the target charge weight.
Variations Across Lee Powder Measure Models
Lee offers several powder measure models, including the Pro Auto Disk Powder Measure, the Lee Perfect Powder Measure, and the Lee Auto-Disk Powder Measure. While the fundamental principle remains the same, the specific chart layouts and adjustment mechanisms may vary slightly. Always consult the chart that accompanies your specific Lee powder measure model.
Proper Use of the Lee Powder Measure Chart & Safe Reloading Practices
Using the Lee powder measure chart correctly is paramount to safe and accurate reloading. Improper use can lead to dangerous overcharges or undercharges, potentially resulting in equipment damage or injury.
Steps to Accurate Powder Dispensing Using the Lee Powder Measure Chart
- Consult the Chart: Begin by identifying your specific powder type on the relevant chart.
- Set the Measure: Carefully adjust the measure to the setting indicated on the chart for your desired charge weight. Make small adjustments to fine-tune the throw weight.
- Test Throws: Never rely solely on the chart. Always conduct several test throws to verify the actual powder charge weight. Weigh each throw on a scale. Small variations are common, and repeated throws will help you determine the consistency of your measure.
- Adjust as Needed: If the test throws consistently show a significant deviation from the target weight, slightly adjust the measure's setting and repeat the test throws until you achieve consistent results within an acceptable tolerance (typically ±0.1 grain for handgun loads and ±0.2 grains for rifle loads).
- Consistency is Key: The goal is consistent powder charges, not precise matches to the chart's listed weights. The chart is a guide, not an absolute measure.
Troubleshooting Common Issues with Lee Powder Measures
Despite their reliability, Lee powder measures can sometimes present challenges. Here's how to troubleshoot some common issues:
- Inconsistent Throws: This often points to a problem with the powder measure's adjustment, the powder itself (clumping, moisture), or a need for thorough cleaning. Try adjusting the measure, using a different batch of powder, and thoroughly cleaning the measure.
- Powder Bridges: This happens when the powder clumps and doesn't flow smoothly. Using a powder funnel and lightly tapping the measure can help. A slightly increased throw weight may also be necessary.
- Low Throw Weight: Double-check your measure's setting. Ensure it's clean and free of obstructions.
Beyond the Chart: Tips for Accurate Reloading
The Lee powder measure chart is an important tool, but several other factors influence accuracy:
- Scale Calibration: Regularly calibrate your powder scale to ensure accuracy.
- Powder Condition: Store your powder in a cool, dry place to prevent clumping and moisture absorption.
- Case Consistency: Use consistently sized and prepared cases.
- Bullet Consistency: Use bullets from the same batch and manufacturer to maintain uniform weight and dimensions.
Conclusion: Mastering your Lee Powder Measure
The Lee powder measure chart is a valuable resource for reloaders. However, it's crucial to understand that it serves as a guide, and consistent testing and careful attention to detail are vital for safe and accurate reloading. Always prioritize safety and double-check your work before firing any reloaded ammunition. With practice and a keen eye for detail, you can master your Lee powder measure and produce consistent, reliable ammunition.