Redding 300 Winchester Magnum Full Length Sizing Die

The Redding 300 Winchester Magnum full length sizing die is built for reloaders who need consistent, reliable case preparation for one of magnum rifle hunting's most capable cartridges. Whether you're loading for a bolt-action hunt or precision range sessions, a full length sizing die is the workhorse that resizes your cases to factory dimensions—critical for reliable feeding and consistent performance across multiple firings. This die handles the entire case, from the neck down through the body, ensuring your 300 Win Mag brass returns to spec after firing.

Redding's engineering means you get a decapping assembly and expander ball included, so you can deprime spent primers and properly bell the case mouth in one setup. This is the foundation of repeatable reloading, especially important when working with magnum cartridges where consistency directly affects velocity and accuracy. If you're building match ammunition or hunting loads that demand precision, proper case sizing is where quality begins.

Setup matters: Redding recommends using a headspace gauge when dialing in your full length die, so your cases are sized to the exact specification your rifle demands. This step takes minutes and pays dividends in reliability and accuracy over the life of your brass. The die is available individually, so you can build your 300 Win Mag die set exactly the way you want it.