RCBS Full Length Die Set for 300 RCM Reloading

The RCBS Full Length Die Set for 300 RCM gives you the two essential dies you need to reload bottleneck rifle cartridges with confidence. Whether you're working up loads for a new rifle or maintaining your ammo supply, this set gets you precisely sized cases and properly seated bullets with the speed and consistency that reloaders depend on.

The Full-Length Sizer Die is the workhorse of the pair. It resizes your cases to SAAMI minimum dimensions, decaps spent primers, and expands the neck to accept your bullet. The die includes vents designed to prevent case damage from trapped air and excessive lube—details that matter when you're processing brass in volume. By holding headspace to minimum tolerances, it protects your case body length during the sizing stroke, a critical factor for consistent pressure and accuracy downrange.

The Seater Die handles the final step: it seats your bullet and secures it with a built-in roll crimper in a single operation. That integrated crimp saves time and ensures your loaded rounds are uniform, shot to shot. Together, these two dies form the foundation of a reliable 300 RCM reloading setup.

Key Features

• Two-die set: Full-Length Sizer Die with Expander-Decapping Unit and Seater Die with Bullet Seater Plug
• Sizes cases to SAAMI minimum cartridge dimensions for safe, consistent performance
• Vented design prevents case damage from trapped air and excessive lubricant
• Integrated roll crimper in Seater Die secures bullets during seating
• Designed for bottleneck rifle cartridges

Specifications

Frequently Asked Questions

What dies do I get in this RCBS 300 RCM set?

You receive a Full-Length Sizer Die with an integral Expander-Decapping Unit and a Seater Die equipped with a Bullet Seater Plug. The sizer handles sizing, decapping, and neck expansion; the seater seats the bullet and applies a roll crimp in one step.

What is the roll crimper for?

The built-in roll crimper in the Seater Die secures the bullet to the case as it's being seated. This helps prevent bullet movement and ensures consistent round-to-round performance.

Will this set work for my 300 RCM rifle?

Yes—this is a dedicated die set for 300 RCM reloading and sizes cases to SAAMI minimum dimensions appropriate for that cartridge.

Does the Sizer Die require external lubrication?

The die is designed with vents to manage trapped air and excessive lubricant, which are common concerns during the full-length sizing process. Proper case lube technique will help ensure smooth operation and case longevity.