The Redding 22-250 Rem Ackley Improved 40° Competition Neck Die Set (MPN: 58406) is a precision 3-die mechanical reloading system engineered specifically for handloading fire-formed .22-250 Remington Ackley Improved cartridges. Built on the industry-standard 7/8″-14 thread interface, this non-powered steel die set fits standard single-stage and turret reloading presses. It provides total control over cartridge concentricity, shoulder position, neck tension, and overall length via three dedicated dies: a Competition Bushing Neck Sizing Die, a dedicated Body Die, and a Competition Bullet Seating Die.

Key Features

• Sliding Sleeve Bushing Neck Sizing: Employs a tight-tolerance sliding alignment sleeve to center the cartridge case before neck sizing occurs, minimizing runout while allowing custom neck tension via interchangeable sizing bushings.
• Micrometer Adjustment Controls: Features top-mounted micrometers on both the neck sizing die (for setting neck sizing depth) and the bullet seating die (for controlling seating depth) calibrated in 0.001″ increments.
• Independent Body Sizing: Includes a dedicated Body Die designed to full-length size the case body and bump back the 40-degree shoulder when bolt closure tightens, without contacting or altering the pre-sized case neck.
• Concentric Bullet Seating: Utilizes a floating seating stem and internal alignment sleeve to support the bullet and case simultaneously, seating projectiles with minimal eccentricity.

Specifications

• Manufacturer Part Number (MPN): 58406
• Calibre Compatibility: .22-250 Remington Ackley Improved (40° shoulder angle only)
• Thread Standard: 7/8″-14 thread interface
• Micrometer Adjustments: 0.001-inch increments
• Die Set Contents: Competition Bushing Neck Sizing Die, Body Die, Competition Seating Die
• Packaged Weight: Approximately 0.8–1.0 kg
• Power Requirement: Manual mechanical operation (0W)

Who is the Redding 22-250 Rem Ackley Improved 40° Competition Neck Die Set for?

• Benchrest competition shooters handloading .22-250 Ackley Improved ammunition — requires the 0.001-inch micrometer increments of this neck die set to establish exact bullet seating depth and uniform neck sizing on brass fire-formed with a 40-degree shoulder.
• Long-range varmint hunters seeking minimum cartridge runout — relies on the tight-tolerance internal sliding alignment sleeves across the standard 7/8″-14 press dies to eliminate cartridge eccentricity and control neck tension independently from body sizing.

Less suitable for: Standard factory .22-250 Remington brass with a 28-degree shoulder, or users requiring ready-to-size equipment out of the box without purchasing separate sizing bushings; use a standard 2-die full-length sizing set configured with an integrated expander ball for non-Ackley chambers.