Reloading ammunition is an art that requires both skill and attention to detail.
One essential component in the process is ensuring that the case’s shoulder is properly bumped back to ensure flawless chambering and firing.
This article will explore the concept of bumping the shoulder back when reloading and provide a comprehensive guide on how to do it correctly.
Understanding the Importance of Bumping the Shoulder Back
- Basics of Case Resizing: During the firing process, the cartridge case expands to fit the chamber of the firearm tightly. When we reload this cartridge, we must resize it so it will fit back into the chamber properly. The shoulder of the cartridge case often needs special attention during this process.
- Chambering and Reliability: Improperly resized cases can lead to chambering issues. If the shoulder isn’t bumped back sufficiently, it may cause the cartridge to be too long for the chamber, leading to failures in chambering the round.
- Ensuring Longevity of Brass: Repeatedly stretching and working the brass can shorten its lifespan. Correctly bumping the shoulder back can reduce undue stress on the brass, ensuring that you can get more reloads out of each case.
- Accuracy and Consistency: Properly resized cartridges provide a consistent foundation for bullet seating, powder measure, and other reloading processes, which can result in improved accuracy when firing.
- Safety Considerations: Incorrectly resized cases can lead to dangerous situations, including over-pressured rounds. It’s crucial for safety reasons to ensure that the shoulder is bumped back correctly.
Tools and Techniques for Bumping the Shoulder Back
- Using a Full-Length Sizing Die: A full-length sizing die resizes the entire case, including the shoulder. By adjusting this die correctly, you can achieve the desired bump on the shoulder.
- Precision Measurement Tools: Tools such as the case gauge or caliper can be used to measure the shoulder’s position before and after resizing. This helps in ensuring that the shoulder has been bumped back the correct amount.
- Lubrication: Adequate lubrication is essential to ensure that the case doesn’t get stuck in the die. It also ensures that the resizing process is smooth, which is crucial for precise shoulder bumping.
- Progressive vs. Single-Stage Presses: While both types of presses can effectively bump the shoulder back, using a single-stage press can often provide more precision as you can handle one cartridge at a time, ensuring meticulous resizing.
- Setting Up the Die: Start by screwing the die into the press until it touches the shell holder. This initial setup might not bump the shoulder back enough, so it’s essential to make small incremental adjustments until you achieve the desired result.
Common Mistakes to Avoid
- Over-Resizing: Pushing the shoulder back too much can make the cartridge too short, which can lead to headspace issues and reduce the life of the brass.
- Insufficient Lubrication: Not using enough lube can result in cases getting stuck in the die. This not only disrupts the reloading process but can also damage both the die and the case.
- Not Measuring Cases: Assuming that the die is set up correctly without measuring can lead to inconsistencies. It’s always a good practice to check and measure, especially when you start a new batch.
- Relying Solely on Factory Settings: While factory settings provide a good starting point, they might not always produce the perfect shoulder bump for your specific firearm. Personal adjustments are often necessary.
- Not Checking for Wear: As with all tools, reloading dies wear over time. Regularly inspect them for wear and tear, and ensure they’re still producing the desired results.
Conclusion
Bumping the shoulder back correctly when reloading is both an art and a science. With the right tools, attention to detail, and understanding of the process, you can achieve consistent and reliable ammunition that is safe to use and maximizes the life of your brass. Whether you’re a seasoned reloader or a beginner, always ensure you measure, adjust, and test to get the best results.
Frequently Asked Questions on Shoulder Bumping in Reloading
1. How much does it cost to bump shoulder reloading?
Answer: The cost to bump the shoulder when reloading is mostly determined by the initial investment in the necessary equipment. If you already have a reloading press, you might just need a full-length sizing die specific to your cartridge type. Prices for these dies can range from $30 to $100 or more, depending on the brand and quality. Remember, premium brands often offer better precision and longevity. Other associated costs include lubricants and measurement tools, such as case gauges or calipers. Over time, however, the cost per round will decrease significantly as you reuse your equipment.
2. What is shoulder bumping in reloading?
Answer: Shoulder bumping in reloading refers to the process of slightly setting back the shoulder of a fired cartridge case to ensure it properly chambers in a firearm. When a cartridge is fired, the case expands, including the shoulder area. During the reloading process, it’s essential to return the shoulder to its correct position to ensure the reloaded cartridge fits well in the chamber and allows for safe and reliable firing. Shoulder bumping ensures that the cartridge has the correct headspace for the specific firearm.
3. Can you shoulder bump with a full-length die?
Answer: Yes, you can bump the shoulder back with a full-length sizing die. A full-length sizing die resizes the entire case body, including the shoulder. By carefully adjusting the die in the reloading press, you can achieve the desired bump on the cartridge shoulder. The degree of adjustment will determine how much the shoulder is set back.
4. Does a neck sizing die bump the shoulder?
Answer: Typically, a neck sizing die is designed to only resize the neck of the cartridge case, ensuring a tight grip on the bullet without working the body and shoulder of the case. Therefore, a standard neck sizing die doesn’t bump the shoulder. However, there are specific neck sizing dies that have a slight shoulder bump feature. These are sometimes called “partial full-length” or “bump-neck” dies. If bumping the shoulder is desired while neck sizing, it’s essential to purchase a die explicitly designed for that purpose.