The Redding 77420 Type S Full Length Sizing Die is a precision reloading tool engineered specifically for the .243 Winchester Improved 40° cartridge. It performs complete case body resizing, bumps the 40° shoulder back to headspace tolerances, and controls neck tension in a single press stroke. Designed with a 7/8"-14 industry-standard thread, this mechanical die operates on standard single-stage and turret reloading presses to deliver precise neck tension while maintaining case concentricity.

Key Features:

• Full-Length Resizing with Shoulder Bump: Restores fired cartridge bodies to chamber dimensions and resets the 40° shoulder for reliable cycling.
• Self-Centring Bushing System: Utilises a freely floating neck bushing that self-aligns on the case neck to minimise runout.
• Adjustable Sizing Depth: The decapping assembly adjusts vertically, allowing partial neck sizing across 1/2 to 3/4 of the neck length.
• Configurable Assembly: Includes a decapping pin retainer to size without an expander button, preventing neck overworking, or can be stripped of internal components to function as a dedicated body die.
• Universal Press Interface: Built with 7/8"-14 threading and an included lock ring to mount securely on standard handloading presses.

Specifications:

• Calibre: .243 Winchester Improved 40° (.243 Win Ackley Improved)
• Bullet Diameter Compatibility: .243" (6mm)
• Thread Size: 7/8"-14 with included 7/8"-14 lock ring
• Shellholder Compatibility: Redding #1 Standard Shellholder (PN 11001) or Competition Shellholder Set #1 (PN 11601)
• Bushing Requirements: Redding interchangeable sizing bushings (typically 0.266" to 0.274" for .243 AI; sold separately)
• Die Weight: Approximately 250 g to 350 g
• Power Requirement: Manual / non-powered mechanical operation

Who is the Redding Type S Bushing Full Length Die for .243 Winchester Ackley Improved for?

• Precision handloaders reloading for bolt-action rifles — Full-length resizes the .243 Winchester Improved 40° case body while allowing fine neck tension adjustments in 0.001" increments using interchangeable bushings.
• Long-range target competitors — Minimises cartridge runout and extends brass life in .243 Winchester Improved 40° chambers by freely floating the sizing bushing to maintain concentricity on standard 7/8"-14 reloading presses.
• Precision varmint and game hunters — Ensures dependable chambering by bumping the 40° shoulder back to spec while setting specific neck tension thresholds, such as 0.002" for magazine-fed hunting rifles.

Less suitable for: Standard factory .243 Winchester cases with 20° shoulders; reloaders working with non-improved brass require a standard 20° full-length sizing die rather than a 40° Ackley Improved bushing die. Radical calibre reductions in a single pass exceed bushing design thresholds and require dedicated case-forming dies.