RCBS 0.337" Neck Bushing

Tailored for precision reloading with RCBS gold medal match series dies, these self-centering neck bushings allow users to fine-tune neck tension, significantly reducing work hardening and boosting case life and shot accuracy. To use them effectively, brass with uniform neck wall thickness is essential. The correct bushing can be found by measuring the neck of a loaded cartridge and subtracting 0.002 - 0.003 inches or by calculating with a formula - double the neck wall thickness, add the bullet diameter and subtract 0.001 inches. Keeping a variety of sizes nearby one or two above and below the target-is highly recommended by RCBS. Proudly made in the USA for superior quality and reliability