The Redding .309 Titanium Nitride Neck Sizing Bushing (MPN 76309) is a precision metallic cartridge reloading component designed to accurately size the outside diameter of cartridge case necks to exactly 0.309 inches. By sizing only the outside of the neck, it eliminates the need for an internal expander ball, minimizing brass working, prolonging case life, and enhancing concentricity. It is constructed from a heat-treated steel substrate with a core hardness of approximately Rc 60–62 and finished with a micro-thin gold Titanium Nitride (TiN) surface coating that reduces friction and prevents brass galling.

Key Features:

• Precise Neck Tension: Regulates case mouth dimension to a consistent 0.309-inch inner diameter to achieve targeted bullet-grip tension.
• Titanium Nitride Coating: Low-friction, ultra-hard TiN surface treatment lowers sizing resistance and protects against brass pickup during repetitive cycles.
• Universal Compatibility: Fits all standard Redding Type S Neck Bushing Dies, Type S Full Length Sizing Dies, and Competition Neck Sizing Dies, while freely interchanging with 1/2-inch outer diameter bushing systems from L.E. Wilson and Hornady.
• Concentricity Optimization: Eliminates the case-distorting expander-button drag stroke to preserve bullet-to-case alignment.

Specifications:

• Inner Sizing Diameter: 0.309 inches
• Outer Diameter: 0.500 inches (1/2 inch)
• Length: 0.375 inches (3/8 inch)
• Weight: Approximately 0.02 lbs (~9 grams)
• Substrate Core Hardness: Heat-treated steel, approx. Rc 60–62
• Surface Treatment: Titanium Nitride (TiN)
• Die System Compatibility: Redding Type S, Redding Competition, and standard 0.500" O.D. die bodies

Who is the Redding .309 Titanium Nitride Neck Sizing Bushing for?

• Benchrest handloaders — achieves exact neck tension on .30-caliber or custom turned cartridge necks via a precise 0.309-inch inner sizing diameter without expanding the case from the inside out.
• F-Class and PRS precision shooters — reduces brass work-hardening and improves concentricity across high-volume firing cycles by using a low-friction Titanium Nitride (TiN) coated reloading neck sizing bushing built to standard 0.500-inch outer diameter die specifications.

Less suitable for: Reloaders whose fired case necks require a reduction of more than 0.008 to 0.010 inches in a single pass; this scenario requires intermediate stepping bushings to prevent neck wrinkling and runout.