Mastering 5.7x28mm Reloading: A Comprehensive Guide to the Lee Factory Crimp Die

For reloaders seeking precision, reliability, and unparalleled ease when handloading the notoriously challenging 5.7x28mm Fabrique Nationale cartridge, the Lee 90725 Factory Short Bottle Neck Crimp Pistol Die emerges as an indispensable tool. This specialized die is engineered to address the unique demands of this high-performance, bottlenecked pistol round, transforming what can often be a frustrating crimping process into a straightforward and highly consistent operation. If you've ever asked, "How do I achieve a reliable crimp on 5.7x28mm?" or "What's the best way to prevent bullet setback in my FNH Five-seveN or PS90 ammunition?", this deep dive into the Lee Factory Crimp Die holds the answers.

Understanding the Unique Challenges of 5.7x28mm Handloading

The 5.7x28mm FN cartridge, known for its small diameter, high velocity, and unique bottleneck design, presents several hurdles for the reloader, particularly concerning bullet retention and consistent feeding. Unlike many pistol cartridges that rely on a simple taper crimp, the 5.7x28mm benefits significantly from a more robust, rifle-type crimp. This is critical for:

• Preventing Bullet Setback: High-capacity magazines and the feeding cycle of firearms like the FN Five-seveN pistol or FN PS90 carbine can exert significant pressure on the bullet, potentially pushing it deeper into the case. This "bullet setback" can lead to dangerous pressure spikes and inconsistent performance.
• Ensuring Consistent Feeding: A properly crimped bullet provides the necessary neck tension to ensure smooth feeding from the magazine into the chamber, reducing the risk of malfunctions.
• Maintaining Accuracy and Velocity Consistency: A uniform crimp contributes to consistent bullet release, which is fundamental for achieving tight groups and predictable muzzle velocities.

Traditional crimping methods often fall short with the 5.7x28mm, especially if the bullet lacks a dedicated crimp groove. This is precisely where the innovative design of the Lee Factory Crimp Die shines.

Why the Lee Factory Crimp Die is a Game Changer for 5.7x28mm Reloading

The core innovation of the Lee 90725 Factory Crimp Die lies in its unique collet system. Instead of simply pressing the case mouth inward with a roll or taper, this die employs a multi-segment collet that uniformly squeezes the case mouth around the bullet. This action results in a distinct, rifle-type crimp that offers superior bullet retention.

Here’s a breakdown of the key benefits and features that make this die an essential component for any 5.7x28mm reloader:

1. Collet-Style, Rifle-Type Crimp: This is the hallmark feature. The collet die applies a powerful, concentric crimp around the entire circumference of the bullet. This type of crimp is far more effective at securely holding the bullet in place compared to standard taper crimps, which are often insufficient for the 5.7x28mm's high-pressure characteristics and feeding demands.
2. Forms a Crimp Groove Where None Exists: Perhaps the most remarkable advantage is its ability to create its own "crimp groove" on bullets that are designed without one. The immense force exerted by the collet can actually form a slight indentation on the bullet's bearing surface, providing a positive, mechanical lock. This feature dramatically expands the range of suitable projectiles for reloading the 5.7x28mm, allowing reloaders to use bullets that might otherwise be problematic.
3. Superior Bullet Retention: The robust crimp produced by this die ensures maximum bullet retention, virtually eliminating the risk of bullet setback during chambering or recoil. This directly translates to enhanced safety and consistent performance.
4. Improved Feeding Reliability: A firm, consistent crimp provides optimal neck tension, which is crucial for smooth and reliable feeding in semi-automatic firearms chambered in 5.7x28mm. This reduces the chances of misfeeds or jams, contributing to a more enjoyable and dependable shooting experience.
5. Enhanced Accuracy and Consistency: By providing a uniform and predictable bullet release, the Lee Factory Crimp Die contributes significantly to improved shot-to-shot consistency in muzzle velocity and, consequently, better accuracy on target.
6. Simplicity of Use: Despite its advanced capabilities, the Lee Factory Crimp Die is straightforward to set up and operate. It integrates seamlessly into standard reloading presses and requires minimal adjustment to achieve optimal results.
7. Extends Case Life: Unlike some aggressive crimping methods that can overwork the brass, the collet crimp applies pressure evenly, which can help in preserving case life over multiple reloading cycles, maximizing your investment in brass.
8. Part of the Renowned Lee Precision Lineup: Lee Precision is a brand synonymous with innovation, quality, and affordability in the reloading community. The 90725 Factory Crimp Die upholds this reputation, offering a robust and effective solution that delivers exceptional value.

How to Achieve Optimal Results with Your Lee 5.7x28mm Factory Crimp Die

To maximize the performance benefits of your Lee Factory Crimp Die, consider these practical tips and best practices:

• Proper Die Setup: Follow the instructions provided with your die carefully. Typically, you'll thread the die into your press until it just touches the shell holder, then lower the ram and turn the die down an additional quarter to half turn. Fine-tune this adjustment based on the desired crimp amount and bullet type.
• Consistent Case Length: While the collet system is forgiving, ensuring consistent case length across your batch of brass will help produce the most uniform crimps. Trim your cases to specification if necessary.
• Bullet Selection: While this die can form a crimp groove on smooth bullets, using bullets with a slight cannelure or crimp groove designed for bottleneck cartridges can further enhance the crimping process and bullet retention. Experiment with various bullet types to find what works best for your specific application and firearm.
• Avoid Over-Crimping: While a strong crimp is desired, excessive crimping can deform the bullet or overwork the brass, potentially leading to reduced accuracy or shortened case life. The collet die allows for a precise, firm crimp without the pitfalls of over-crimping.
• Test Your Reloads: Always conduct thorough function tests of your reloads in your firearm before engaging in extensive shooting. Check for proper feeding, chambering, and extraction. Measure overall length (OAL) before and after chambering a few rounds to detect any signs of bullet setback.

Addressing Common Questions from 5.7x28mm Reloaders

Q: Can I use this die with any 5.7x28mm bullet?
A: Yes, one of the primary advantages of the Lee Factory Crimp Die is its ability to apply a secure crimp even to bullets without a dedicated crimp groove, by forming one. This significantly expands your bullet choices for 5.7x28mm handloading.

Q: Is a factory crimp necessary for 5.7x28mm?
A: While some reloaders might skip it for certain calibers, for the 5.7x28mm, a strong, consistent crimp is highly recommended. Its bottleneck design, high pressures, and the feeding dynamics of firearms like the FN Five-seveN and PS90 make bullet retention paramount for safety and reliability. The Lee Factory Crimp Die provides the ideal solution.

Q: How does this die compare to other crimp dies?
A: Unlike roll crimp dies (which are generally for rimmed cartridges) or basic taper crimp dies (which are common for straight-walled pistol cartridges), the Lee Factory Crimp Die for bottleneck cartridges utilizes a collet. This collet system applies a uniform, circumferential crimp that mimics a rifle-type crimp, offering superior bullet retention and solving issues like setback that other crimp methods may not adequately address for high-velocity, bottleneck pistol rounds.

Q: Will this die improve the accuracy of my 5.7x28mm reloads?
A: While accuracy is a result of many factors (powder charge consistency, bullet concentricity, primer seating depth, etc.), a consistent and proper crimp contributes significantly to uniform bullet release from the case. This uniformity is a key factor in achieving tighter groups and greater shot-to-shot consistency, thus indirectly improving overall accuracy.

Why Choose Lee Precision?

Lee Precision has been a trusted name in reloading equipment for decades, known for its innovative designs that make reloading more accessible, efficient, and precise. The Lee Factory Crimp Die is a testament to their commitment to solving real-world reloading challenges. By focusing on practical solutions and durable construction, Lee ensures that their tools provide exceptional performance and longevity for both novice and experienced reloaders. The engineering behind the collet system in the Lee 90725 is a prime example of their problem-solving approach, delivering a professional-grade crimp typically associated with custom ammunition, right from your reloading bench.

When you invest in Lee Precision products, you're not just buying a tool; you're gaining access to a legacy of reloading expertise and innovation designed to help you produce superior ammunition. The value offered by Lee products, including this essential 5.7x28mm crimp die, is consistently highlighted by reloaders who prioritize both quality and affordability.

The Final Word: Secure Your 5.7x28mm Reloads with Confidence

The Lee 90725 Factory Short Bottle Neck Crimp Pistol Die for 5.7x28mm Fabrique Nationale is more than just another reloading accessory; it's a critical component for anyone serious about handloading this unique and high-performance cartridge. It solves the inherent challenges of crimping bottleneck pistol rounds, ensuring maximum bullet retention, promoting reliable feeding, and contributing to overall ammunition consistency and safety.

By providing a robust, rifle-type crimp that can even form a groove on otherwise smooth bullets, this die simplifies the reloading process and empowers you to produce high-quality, reliable ammunition for your FN Five-seveN, PS90, or other 5.7x28mm firearms. It is an investment that pays dividends in reduced frustration, enhanced performance, and peace of mind on the range or in the field.

This exceptional Lee Precision Factory Crimp Die, designed to elevate your 5.7x28mm reloading experience, is readily available to help you achieve the consistent, secure ammunition you demand. You can find this essential reloading tool and a wide range of other Lee Precision products at DEGuns.com.

Feature	Description	Benefit for 5.7x28mm
Brand	Lee Precision	A leading, trusted name in reloading equipment known for innovation and value.
Model/Series	Factory Crimp Die (Bottle Neck)	Specifically designed for bottleneck pistol cartridges like 5.7x28mm FN.
Die Type	Collet Crimp Die	Applies a uniform, powerful rifle-type crimp, preventing bullet setback and enhancing feeding.
Caliber	5.7x28mm Fabrique Nationale	Precision-engineered for the unique crimping requirements of this high-performance cartridge.
Bullet Compatibility	Crimp can be applied to bullets with or without a crimp groove, as the die will form one.	Expands bullet selection, allowing use of projectiles not traditionally designed for crimping.
Contents	1 Die (no shell holder included, designed for use with your existing shell holder for 5.7x28mm cases)	Focuses on the specific crimping function, assuming standard reloading setup.
Manufacturer Part Number (MPN)	90725	Unique identifier for this specific product, ensuring you get the correct die for your needs.
UPC	734307907259	Universal Product Code for easy identification and purchasing.
SKU	6660	Stock Keeping Unit, used internally for inventory management by retailers like DEGuns.