The Redding Tapered Size Button (.30 Cal to .375 Cal) is a precision-machined, heat-treated steel reloading component engineered for neck-forming and expanding bottleneck cartridge cases. Designed to thread directly onto standard Redding decapping rod assemblies within full-length and Type "S" bushing sizing dies, this mechanical expander button uses a gradual taper to expand parent brass from a .308-inch inside neck diameter up to .375 calibre in a single pass without collapsing or distorting the case shoulder.

Key Features

• Smooth Tapered Profile: Features an extended, gradual taper that smoothly expands brass case necks rather than abruptly forcing them open, preventing shoulder buckling.
• Single-Pass Case Forming: Engineered specifically for wildcatting and neck up-sizing, taking parent .30-calibre brass up to .375 calibre in one operation.
• Heat-Treated Steel Construction: Machined from solid steel and heat-treated to resist wear and maintain dimensional consistency over repeated sizing cycles.
• Consistent Neck Tension: Sets and aligns the inside neck diameter of .375-calibre cartridges to ensure uniform bullet seating depth and release pressure.
• Redding Die Compatibility: Threads directly onto decapping rod assemblies in both standard Redding Full Length sizing dies and Type "S" bushing dies.

Product Specifications

• Manufacturer Part Number (MPN): 16373
• Expansion Range: .308 in (.30 cal) parent bore up to .375 in (.375 cal)
• Material: Heat-treated, precision-machined steel
• Power Requirements: None (0V, fully manual benchtop component)
• Packaged Dimensions: 2 × 3 × 0.5 inches (50.8 × 76.2 × 12.7 mm)
• Packaged Weight: Approximately 0.08 lbs (36.3 g)

Who is the Redding Tapered Size Button From 30 Cal To 375 Cal for?

• Wildcatters and Handloaders Forming Custom Brass — Expands parent bottleneck cases starting from a .308-inch bore up to .375 calibre in a single pass, allowing reloaders to form cartridges such as .375 Whelen or .375 Winchester without crushing case shoulders.
• Medium-to-Big-Bore Reloaders — Delivers uniform inside neck expansion for .375-calibre dangerous game cartridges using standard Redding sizing dies, weighing approximately 36.3 g in a 2 × 3 × 0.5 inch package.

Less suitable for: Expanding case necks beyond .375 calibre (such as stepping up to .416 or .458 cal), which requires dedicated multi-stage expanders; high-volume standard sizing without inside-neck lubrication, which is better served by free-floating carbide size buttons; or ultra-precision match neck control, which is better suited to neck-turning mandrel systems or bushing dies operated without an expander ball.