RCBS Neck Expander Plug for .310 SB

The RCBS Neck Expander Plug for .310 SB is a precision replacement component designed for reloaders who demand consistency and accuracy in their ammunition production. This expander plug is specifically engineered for the .310 SB cartridge, making it an essential tool for both competitive shooters and serious handloaders. Whether you're preparing rounds for long-range hunting or target shooting, maintaining quality expander plugs ensures your reloading process remains efficient.

This plug works in conjunction with RCBS Neck Expander Dies to properly size and prepare cartridge necks, providing precise inside-neck expansion that removes sizing lubricant and prepares the neck for bullet seating. RCBS expander plugs are manufactured to tight tolerances, ensuring uniform neck wall thickness and concentricity—critical factors that directly impact bullet fit, powder charge uniformity, and overall shot-to-shot consistency.

Reloaders working with the .310 SB cartridge will find this RCBS Neck Expander Plug (MPN 39869) an affordable way to maintain their die's performance and extend its service life. Its compact design and lightweight nature make it easy to store and integrate into your reloading press setup without adding bulk or unnecessary complexity to your bench.