The RCBS Lube-A-Matic .431 bullet sizing die is a reloading die designed to size and lubricate bullets as part of a lube-sizer system. It features a hardened interior to help maintain alignment of cylindrical bullets and is configured to perform gas-check crimping on compatible bullet styles. This die is intended for use in the RCBS Lube-A-Matic two-bullet sizer/lubricator and is compatible with the Lyman 450/4500 lube sizer.
Key Specifications
- The bullet diameter is .431 inches.
- Designed for use with the Lube-A-Matic two-bullet sizer/lubricator and Lyman 450/4500 lube sizer.
- The die performs both bullet sizing and lubrication to ease handling of harder lubricants.
- It features a hardened interior intended to improve alignment for cylindrical bullet shapes.
- The unit can crimp gas checks on compatible bullet styles.
- This die is part of an RCBS series covering diameters including .22, .26, .244, .312, .321, .354, .355, .356, .357, .376, .400, .401, .417, .427, .429, .430, .431, .450, .451, .452, .454, .457, .458, and .500.
- Intended for use with many common handgun and rifle bullet calibers when paired with a compatible lube-sizer system.
Engineered for bench reloading workflows, the RCBS Lube-A-Matic .431 die integrates sizing, lubrication, and gas-check crimping functions to streamline bullet preparation. Its hardened interior and compatibility with common lube-sizer systems make it a practical, durable addition to a reloader’s tooling collection.
This description was generated with AI and may contain errors. Verify specifications and legal restrictions with the manufacturer before purchase. Provided “as-is” without warranties or guarantees.




