Rcbs X Die Full Length Set .300 Wby

The RCBS X Die Full Length Set for .300 Weatherby Magnum is built for reloaders who want to cut down on trimming work without sacrificing case longevity or accuracy. This two-die set includes an X Die sizer and a standard seater die, engineered to minimize the case growth that typically requires repeated trimming after the first reload. If you're loading for a .300 Wby and tired of trimming cases every few reloading cycles, this system addresses one of the most time-consuming parts of precision reloading.

The key to the X Die's design is its specially engineered mandrel, which features an integrated expander ball and decapping pin. As you resize, the mandrel works to reduce the growth that occurs when the case neck contacts the die wall—a problem that forces most reloaders into frequent trimming. The close tolerance between mandrel and die neck prevents the neck wall from thickening as the case is pushed back, meaning your .300 Wby cases will stabilize at a consistent length well below maximum spec and stay there through multiple reloads.

Your workflow changes noticeably: trim your cases once at the start to .020 inch below maximum length, then load with confidence that growth will be minimal and predictable. Cases will grow slightly during the first few reloads, then stabilize—no additional trimming needed, no measurable loss of accuracy or case life. For reloaders who already own a standard die set for .300 Weatherby, you can purchase the X Die sizer separately rather than buying the full set.

Key Features

• Full length sizing die with integrated expander ball and decapping pin for .300 Weatherby Magnum
• Patented mandrel design minimizes case growth, eliminating repeated trimming
• Includes standard seater die for complete reloading
• Cases stabilize quickly and remain consistent through multiple reloads
• Reduces neck wall thickening for longer case life
• X Die sizer can be purchased separately for those who already own a standard seater die

Specifications

Frequently Asked Questions

How much do I need to trim my cases initially?

Trim your cases once at the beginning to .020 inch off the maximum length to standardize them. After that initial trim, the X Die's design keeps growth minimal, and additional trimming is not necessary.

Can I use just the X Die sizer if I already have a seater die?

Yes. If you already own a standard seater die for .300 Weatherby Magnum, you can purchase the X Die sizer separately instead of buying the full set.

Will using the X Die affect my case life or accuracy?

No. Cases sized repeatedly in the X Die will grow slightly at first, then stabilize below maximum case length with no discernible loss of accuracy or case life.