Modular Sizing Die – Dasher

After studying precision CNC machines and tooling, we designed the Modular Sizing Die with shallow tapers instead of threads to securely center the Solid Decapping Pin. This tapered design achieves unmatched concentricity and repeatability.

Additionally, our die sizes slightly more at the base and less at the shoulder compared to most resizing dies on the market. This design helps eliminate extraction issues in properly sized rifle chambers and reduces case runout, avoiding excessive shoulder sizing.

Modular Sizing Die Assembly

• Modular Sizing Die Body: Features standard 7/8 x 14 threads, 17-4 Stainless Steel construction, and a special Salt Bath Nitride finish to enhance lubricity and performance.
• Universal Solid Decapping Pin: Made from high-strength 1144 Stress Proof Steel, with a .058” nominal diameter tip to fit small primer flash holes. You can adjust the Solid Decapping Pin’s protrusion by repositioning the wide-mouth retaining clip.
• Knurled ER11 Top Cap: The ¾ x 24 Threads tighten the Knurled ER11 Top Cap into the die body, compressing the ER11 collet, which securely holds the Decapping Pin or Expander Mandrel to ensure concentricity.
• ER11 Collet: A commercially available ER11 collet secures various Decapping Pin and Expander Mandrel diameters.
• Taper Adapter: When you thread the Knurled ER11 Top Cap into the die body, it seats the ER11 Collet into the Taper Adapter, locking the Decapping Pin or Expander Mandrel. The Taper Adapter sits directly above the Neck/Shoulder Sizing Bushing, allowing the Neck/Shoulder Sizing Bushing to float.
• Neck / Shoulder Bushings: Available in various caliber-specific neck diameters. You can add .001” shims above the Neck/Shoulder Bushing to adjust headspace without threading the die in or out, similar to traditional dies.

Steps to Set Up Your Short Action Customs Modular Sizing Die

• Ensure the resizing die interior is clean and free of debris. We recommend using a .40 caliber plastic pistol brush with a 12-gauge shotgun patch for cleaning.
• Assemble your Modular die as shown in the image below.
• Raise the reloading press ram fully, thread the resizing die into the top of the press, and continue threading until the die body touches the shell holder. Lower the ram slightly to achieve a “cam over” with the press, then tighten the die body lock ring. If you’re using the Area 419 Zero Press, thread in your die approximately 1/8″ of a turn after it touches the shell holder.
• Use a headspace comparator that contacts the brass shoulder to establish the fired brass headspace.
• Lubricate a clean, fired brass case and cycle it through the Modular Sizing die using a smooth, consistent ram stroke.
• Measure your sized brass and compare it to the fired brass. For most shooting applications, we recommend reducing the fired brass headspace by .001”-.003”.
• To adjust sized brass headspace, thread the resizing die body into the press more or less. We also recommend using Redding Competition Shell Holders. You can also remove or add custom .001″ shims, included with your die, between the “Neck/Shoulder Bushing” and the “Taper Adapter” to adjust headspace.

What’s in the Package

• Modular Sizing Die Body
• Standard orange or grey lock ring
• ER11 Top Cap
• Taper Adapter
• ER11 Collet
• Decapping Pin
• (4) .001″ Shims
• Cardboard Shipping box