Lyman H&i Sizing Die .431

• .431 sizing diameter: Sizes cast bullets to .431 for consistent fit in suitable .44-caliber applications, helping maintain uniform bore engagement and steadier accuracy.
• Body sizing operation: This die is built specifically to size the bullet body cleanly and evenly, which supports reliable chambering and more consistent downrange performance.
• H&I die design: Used with Lyman lube-sizing equipment, the H&I format lets bullet sizing and lubrication work together in one workflow, saving time at the bench.
• Steel construction: A steel sizing die stands up well to repeated use and helps preserve dimensional consistency over long reloading sessions.
• Standard 7/8"-14 compatibility: The standard thread pattern makes integration straightforward with compatible reloading setups, reducing the need for specialized mounting hardware.

About the H&I Sizing Die Series

Lyman H&I Sizing Dies are part of the company’s long-established bullet-casting and reloading range, aimed at reloaders who cast their own bullets and want tighter control over final bullet diameter. Within Lyman’s lineup, these dies serve the practical step between casting and loading, allowing the user to bring bullets to a chosen finished size while working with compatible lube-sizing equipment. That makes them especially relevant for shooters who tune cast-bullet loads for revolvers, lever-action rifles, and other firearms where bullet fit has a direct effect on accuracy and leading.

The series is defined by a straightforward mechanical design focused on repeatable sizing rather than unnecessary complexity. Improved 90° hole spacing is intended to make lubrication easier even with harder bullet lubes, while a tapered mouth helps guide bullets into the die smoothly. Lyman also uses a hardened interior to support alignment and maintain a consistent cylindrical shape through repeated use. Available across a wide range of diameters, the H&I series gives cast-bullet reloaders a practical way to match bullet size to caliber, firearm, and load preference.

About the Lyman H&i Sizing Die .431

The Lyman H&i Sizing Die .431 is intended for reloaders who need a .431 finished bullet diameter for cast-bullet applications. In practical terms, that matters because cast bullets often perform best when their diameter is matched carefully to the firearm and load. A properly sized bullet can improve bore fit, reduce gas blow-by, and support more uniform accuracy, particularly in handgun and revolver cartridges that commonly use this diameter range.

As a body sizing die, this model is built to reshape the bullet body consistently rather than perform multiple die functions at once. That focused role makes it a useful bench tool for reloaders who want predictable results from cast projectiles before seating and crimping. Its steel construction supports durability and dimensional stability over repeated use, which is important when processing batches of bullets where consistency from one piece to the next matters more than speed alone.

The die follows the standard 7/8"-14 thread pattern and uses Lyman’s established H&I format, making it a practical fit within traditional casting and bullet-prep workflows. For reloaders using compatible Lyman lube-sizing equipment, this die supports an efficient process that combines bullet sizing with lubrication. The result is a cleaner, more controlled preparation step for cast bullets intended for accurate and dependable handloads.

About Lyman

The Lyman Gun Sight Company began in 1878 in Middlefield, Connecticut, and the brand remains closely associated with shooting and reloading equipment. Over time, Lyman expanded from sighting products into a broader range of tools for handloaders and bullet casters, including reloading dies, presses, bullet-casting equipment, and gun sights. That long involvement in both shooting accessories and ammunition preparation gives the company a strong connection to traditional bench work as well as field use.

Today, Lyman Products is headquartered in Middletown, Connecticut. The company’s history in reloading was strengthened when it acquired the Ideal reloading-tool business in 1925, helping establish Lyman as a familiar name for reloaders who value practical, workshop-oriented tools. Its product range continues to focus on equipment designed for repeatable results, from case preparation and die systems to bullet casting and sighting solutions.

Main Features

• Manufacturer: Lyman
• Made in: USA
• Category: Bullet Sizing
• Die operation: Body sizing
• Pack size: Single
• Die type: Standard
• Bushing: No
• Case type: Universal
• Sizing die material: Steel
• Adjustment: Standard
• Press compatibility: Standard 7/8"-14 thread
• Bullet diameter: 10.95 mm
• Bullet diameter: 431.00 inch

Warranty

Lyman provides a 2-year warranty for this product. That stated warranty period covers the die as a manufactured tool and adds clear long-term support for regular reloading use.