Redding Competition Rifle Seating Die, .300 Win Mag

Redding designed the Redding Competition Rifle Seating Die, .300 Win Mag for .300 Win Mag (Redding part no. 55153) as a straight-line seater that eliminates the runout typical of ordinary seating dies. The case and bullet are fully supported and aligned in a close-fitting sleeve before seating even starts, and the seating stem itself is precision-ground to match the bullet’s exact diameter, so there’s no play for the bullet to wander off-axis. It’s built for the .300 Win Mag handloader chasing single-digit runout at the bench, not a general-purpose seater. Not rated for compressed loads. Part of the Redding line of reloading dies.

Key Specifications

• The seating stem is precision-ground to match bullet diameter exactly, removing the play that lets ordinary seating stems tip a bullet off-axis.
• The case and bullet are fully supported in a close-fitting alignment sleeve before the seating stroke begins, which is what drives down runout versus a standard seater.
• A micrometer calibrated in .001 inch increments gives precise, infinitely adjustable seating-depth control with no clicks to round the setting off.
• The micrometer has a settable reference feature, so a proven seating depth for this rifle can be dialed back in without re-measuring from zero.
• The die is machined specifically for .300 Win Mag brass and bullet diameter, not a universal fit across calibers.
• Redding rates the die not for use with compressed loads, a real limitation to know before pairing it with a compressed-charge recipe.

Frequently Asked Questions

What makes this different from a standard seating die? The case and bullet are held in a close-fitting alignment sleeve and the seating stem is ground to match bullet diameter, which is what cuts runout compared to a typical seater.

Can I return to a seating depth I’ve already dialed in? Yes, the micrometer has a settable reference feature so a known-good seating depth can be reset without measuring from scratch.

Is this seater specific to .300 Win Mag? Yes, the seating stem and body are machined for .300 Win Mag bullet diameter and case dimensions, not a multi-caliber fit.

Buy the Redding Competition Rifle Seating Die, .300 Win Mag

Order the Redding Competition Rifle Seating Die, .300 Win Mag from Redding through our reloading dies selection and tighten up seating consistency on your .300 Win Mag loads. It ships direct with no FFL required — order it from our Lubbock, Texas gun shop for fast, insured shipping.