The .45-70 Government cartridge, a venerable round with a rich history, continues to be a popular choice for hunters and shooters alike. Its power and accuracy, especially when using cast bullets, make it a compelling option. This guide delves into the intricacies of reloading .45-70 cast bullets, providing you with the knowledge and techniques needed to safely and effectively produce your own ammunition. We'll cover everything from choosing the right components to fine-tuning your loads for optimal performance.
Choosing Your Cast Bullets
Selecting the right cast bullet is paramount to successful .45-70 reloading. Several factors influence your choice:
Bullet Diameter and Weight
The .45-70's bore diameter is nominally .458 inches, but variations exist. You'll find cast bullets ranging from .457" to .460" in diameter. Heavier bullets generally offer greater penetration and energy downrange. Popular weights include 300, 350, 405, and 500 grains. The ideal bullet diameter often requires some experimentation to determine what your rifle prefers for best accuracy. Starting with a bullet slightly larger than the bore diameter (.458-.460") is a common practice, as it helps to obtain a good seal in the barrel.
Bullet Design
Various bullet designs influence ballistics and performance:
- Round Nose: Simple, economical design offering decent accuracy at shorter ranges.
- Flat Nose: Provides greater stopping power at close ranges.
- Semi-wadcutter: Designed for target shooting, offering good accuracy and clean cutting of paper targets.
- Gas Check: Incorporates a gas check to reduce leading, especially important at higher velocities. This is often recommended for .45-70 cast bullet reloading.
Bullet Hardness
Bullet hardness, measured in Brinell Hardness Number (BHN), is crucial. A higher BHN indicates greater hardness, vital for preventing leading in the barrel. A BHN of 10-16 is often recommended for .45-70 cast bullets fired at moderate velocities. Using a bullet that's too soft can lead to excessive leading, causing accuracy problems and potentially damaging your rifle.
Reloading Components: Beyond the Bullet
Successful reloading requires high-quality components. Here's what you'll need:
- Cases: .45-70 brass cases are readily available from various manufacturers. Proper case preparation, including cleaning, resizing, and trimming, is essential.
- Powder: Numerous powders work well with .45-70 cast bullets. Consult your reloading manual for recommended powders and loading data specific to your chosen bullet weight and case. Always start at the minimum recommended charge and work up gradually.
- Primers: Large rifle primers are used in .45-70 cartridges. Use only primers that are compatible with your chosen powder.
- Lubricant: Lubricating your cast bullets is essential to reduce friction and leading. There are various lubricants available, both liquid and powder.
The Reloading Process: Step-by-Step
Reloading involves several critical steps:
- Case Preparation: Clean, resize, and trim your cases to ensure consistent sizing and proper headspace.
- Bullet Lubrication: Apply a suitable lubricant to your bullets to minimize leading.
- Powder Charging: Accurately measure and charge the correct amount of powder into each case. Use a powder scale to ensure consistency.
- Seating the Bullet: Seat the bullet to the correct depth, ensuring sufficient crimp for proper case stability.
- Crimping: Crimp the case mouth to firmly secure the bullet.
- Priming: Carefully seat a large rifle primer into each case.
Caution: Always follow the safety procedures outlined in your reloading manual. Improper reloading can lead to dangerous malfunctions.
Troubleshooting Common Issues
- Leading: Excessive leading usually indicates insufficient bullet hardness or lubricant, or perhaps excessively high velocities.
- Inaccurate Loads: Inconsistent case preparation, poor powder charges, or bullet seating depth can affect accuracy.
- Squib Loads: This dangerous situation occurs when insufficient powder is used, resulting in a bullet that doesn't exit the barrel properly.
Case Study: A Successful .45-70 Cast Bullet Load
Let's look at an example load that often performs well in many .45-70 rifles:
| Component | Specification |
|---|---|
| Case | Once-fired .45-70 brass |
| Bullet | 405-grain, .458" diameter, gas-checked, 12 BHN |
| Powder | 40 grains of IMR 4198 (Check your manual!) |
| Primer | CCI Large Rifle Magnum Primer |
| COL | 2.550" (Check your seating die settings!) |
Disclaimer: This is just an example load. Always consult your reloading manual for specific data for your chosen components and rifle. Start with minimum loads and work up gradually while carefully monitoring pressure signs.
Conclusion: Enjoying the Rewards of Reloading
Reloading your own .45-70 cast bullets can be a rewarding experience, offering cost savings, and the ability to tailor your ammunition to your specific needs. However, it's crucial to emphasize safety and accuracy. Careful attention to detail and the use of a reliable reloading manual are key to success. Remember: safety first. Happy reloading!