Lee Precision 91167 Factory Crimp Die 450 Bushmaster

The Lee Precision Factory Crimp Die for 450 Bushmaster is a specialized reloading die that takes bullet seating one step further—it applies a firm, controlled crimp that holds the bullet in place more securely than standard seating alone. Whether you're loading match-grade 450 Bushmaster rounds for your AR or fine-tuning accuracy for hunting, a proper crimp is often the overlooked detail that tightens your groups. This die uses a collet design that squeezes the case mouth into the bullet's crimp groove, ensuring consistent bullet pull and more uniform chamber pressure.

A firm crimp improves accuracy by raising the initial pressure threshold—the bullet won't shift as pressure builds, which means your pressure curve stays more uniform shot to shot and velocity variation decreases. Tests have shown that even bullets without a dedicated crimp groove shoot more accurately when processed through a factory crimp die, making this tool valuable for handloaders chasing consistency and performance.

The Lee Factory Crimp Die threads into any standard 7/8"-14 reloading press, so if you're already set up for 450 Bushmaster, integration is straightforward. Keep in mind that a shellholder is not included—you'll need to have or source one separately if you don't already own it. This die is a straightforward, no-frills addition to your 450 Bushmaster reloading bench for shooters who understand that precision starts with attention to detail.

Key Features

• Collet-style crimp applies firm, uniform pressure to the case mouth and bullet
• Improves accuracy by stabilizing pressure curves and reducing velocity variation
• Works with 450 Bushmaster ammunition
• Compatible with all 7/8"-14 threaded reloading presses
• Proven to enhance accuracy even on bullets without a crimp groove

Specifications

Frequently Asked Questions

Will this die work in my reloading press?

The Lee Factory Crimp Die is designed for any reloading press with a standard 7/8"-14 thread. If your press accepts standard dies, this will fit.

What's the difference between this and a standard seating die?

A factory crimp die applies a more controlled, firmer crimp than a conventional seating die. This crimp improves accuracy by creating a higher initial pressure threshold, which promotes a more uniform pressure curve and reduces shot-to-shot velocity variation.

Do I need a shellholder for this die?

A shellholder is not included with this die. If you don't already own one for 450 Bushmaster, you'll need to purchase it separately.

Can I use this on bullets without a crimp groove?

Yes. Lee's design has been tested on bullets without dedicated crimp grooves, and accuracy still improves compared to using no crimp at all.