Lee Undersized Carbide Sizing die 40 S&W / 10mm

The Lee Undersized Carbide Sizing die for 40 S&W / 10mm is built for reloaders who want a sizing solution that requires zero case lube and delivers a cleaner, more professional-looking finished round. Carbide's exceptional hardness means you can size cases dry—no messy lubrication, no cleanup, and no risk of lube residue affecting your ammunition. This die also burnishes the case as it sizes, actually improving the case appearance and giving your reloads a polished, factory-like finish.

Carbide sizing dies are an investment in durability. Because of carbide's extreme hardness and wear resistance, this die is built to last a lifetime of reloading without degradation. If you're loading high volumes of 40 S&W or 10mm—whether for competition, duty practice, or hunting—the minimal maintenance and permanent reliability of a carbide die make it a smart long-term choice.

This is an undersized die, meaning it reduces case diameter slightly more than standard sizing. Whether you're working with range brass, once-fired cases, or mixed headstamp lots, an undersized die ensures consistent, snug fit in the chamber and reliable feeding. Pair this with your Lee press (single stage or turret) for straightforward, no-fuss sizing that keeps your reloading sessions moving and your cases in top condition.

Key Features

• Carbide construction requires no case lubrication
• Burnishes cases during sizing for improved appearance
• Undersized for consistent fit and reliable chambering
• Built to last a lifetime with minimal wear
• Works with standard Lee presses

Specifications

Frequently Asked Questions

Do I need to use case lube with a carbide sizing die?

No. Carbide is hard enough that cases can be sized dry without lubrication. This eliminates lube cleanup and the mess that comes with oil-based case lube.

What does undersized mean, and why would I want it?

An undersized die reduces case diameter slightly more than a standard sizing die. This ensures a snug fit in the chamber and promotes reliable feeding, especially useful when working with mixed or once-fired brass.

Will this die wear out?

Carbide is extremely hard and wear-resistant. This die is built to last a lifetime of reloading without degradation, making it a durable long-term investment.

What press do I need to use this die?

This sizing die works with standard Lee presses, including single-stage and turret models. Verify your press compatibility before ordering.