Lyman Pro Micrometer Seating Die 40 S&W/10Mm

The Lyman Pro Micrometer Seating Die for 40 S&W/10mm brings precision bullet seating to your handgun reloading bench. If you're loading for 40 or 10mm and want repeatable, accurate cartridge assembly with minimal bullet run-out, this die gives you the fine adjustment control that separates quality reloads from good-enough ones. The micrometer adjustable seating head lets you dial in exact seating depth to the thousandth of an inch, then hold that setting shot after shot without guesswork or trial-and-error trimming.

The floating bullet seating punch centers each bullet on the case mouth before it engages the seating stem, which reduces run-out and keeps your rounds concentric. That matters: poor run-out means unpredictable bullet alignment in the chamber, which hurts accuracy and can cause pressure inconsistencies. Built from corrosion-resistant stainless steel, this die resists rust and discoloration over years of use, keeping your investment looking and performing like new.

Whether you're fine-tuning loads for competition, hunting, or just chasing tighter groups at the range, a quality micrometer seating die is one of the best upgrades a handgun reloader can make. This one is caliber-specific to 40 S&W and 10mm, so it threads directly into your press and integrates with standard reloading setups.

Key Features

• Micrometer adjustable seating head for precise, repeatable bullet seating depth
• Floating bullet seating punch centers bullets on case and minimizes run-out
• Corrosion-resistant stainless steel construction for durability and long-term appearance
• Caliber-specific design for 40 S&W and 10mm cartridges
• Fine adjustment in thousandths of an inch for handloaded accuracy

Specifications

Frequently Asked Questions

What calibers does this seating die fit?

This die is designed specifically for 40 S&W and 10mm cartridges.

Will this work with my reloading press?

Yes, this is a standard threaded reloading die that will work with any conventional single-stage or progressive press that accepts standard die threads.

How does the micrometer adjustment work?

The micrometer head adjusts in fine increments (thousandths of an inch) to control exactly how deep the bullet seats into the case. Once you dial in your preferred seating depth, you can lock it and repeat that exact setting for consistent, uniform cartridge assembly.

What's the benefit of the floating punch?

The floating punch automatically centers the bullet on the case before seating begins, which reduces bullet run-out and ensures concentric, accurate reloads that perform better in the chamber.