The Redding 71275 Type S Neck Bushing Die is a dedicated reloading die engineered for precision handloaders working with the .300 Remington Short Action Ultra Magnum (.300 RSAUM) cartridge. Designed to size fire-formed brass for consistent bolt-action chamber fitment, it controls bullet neck tension by using freely floating, interchangeable sizing bushings available in 0.001-inch increments. By sizing only the case neck and leaving the case body and shoulder at fire-formed chamber dimensions, this die prevents over-working the brass and extends case life across repeated firings.

Key Features:

• Precision Neck Tension Management: Accepts interchangeable self-centering neck bushings (sold separately) in 0.001-inch increments, enabling exact tension adjustments tailored to specific brass neck wall thicknesses and 0.308 in (7.82 mm) diameter bullets.
• Dual Expander Configurations: Can be run with the included expander size button (#40307) or converted using the supplied decapping pin retainer (#10196) to size necks entirely without an expander ball, minimising brass stretch and runout.
• Adjustable Sizing Depth: The decapping rod assembly (#21308) allows reloaders to adjust the bushing position to size either the entire neck or a fraction (such as one-half to two-thirds) of the neck length, preserving case-to-chamber alignment.
• Standard Press Integration: Built with industry-standard 7/8"-14 threads to mount directly into standard single-stage and turret reloading presses.

Product Specifications:

• Calibre Compatibility: .300 Remington Short Action Ultra Magnum (.300 RSAUM)
• Bullet Diameter Compatibility: 0.308 in (7.82 mm)
• Die Thread Standard: 7/8"-14 thread
• Shellholder Fitment: Redding Shellholder #6 (Part #11006) or Competition Shellholder Set #6 (#11606) (sold separately)
• Internal Components Included: Decapping rod assembly (#21308), expander size button (#40307), decapping pin (#01060), and decapping pin retainer (#10196)
• Operation: Fully manual mechanical reloading tool (0W unpowered)
• Weight: Approximately 200–300 g (7–10 oz)

Who is the Redding Type S Bushing Neck Sizing Die for .300 RSAUM for?

• Long-range precision shooters loading .300 RSAUM — requires exact neck tension control for 0.308 in (7.82 mm) projectiles across standard 7/8"-14 threaded reloading presses, ensuring uniform bullet release velocity without over-working brass.
• Benchrest and F-Class competitors firing bolt-action rifles — sizes only the neck of fire-formed .300 RSAUM cases to match the rifle's specific chamber, using interchangeable bushings in 0.001 in increments to preserve precise concentricity.
• Handloaders seeking to minimise brass work-hardening for single-chamber firearms — allows partial neck sizing and eliminates internal expander ball drag on 0.308 in (7.82 mm) case necks using a dedicated neck bushing sizing die, maximising cartridge case life.

Less suitable for: Handloaders processing brass that has become difficult to chamber due to shoulder growth after multiple high-pressure firings, or those reloading for semi-automatic actions and mixed chambers; these conditions require stepping up to a dedicated body die or switching to a full-length bushing sizing die.