The RCBS 15301 Full-Length 2-Die Set for 300 Win Mag is the foundation of a reliable reloading operation for one of hunting and long-range shooting's most popular magnum cartridges. This matched pair—a full-length sizing die and a seating die—handles the core resizing and ammunition assembly work that keeps your 300 Winchester Magnum brass shooting true and your rounds loading consistent, shot after shot. Whether you're a new reloader building your first setup or an experienced handloader maintaining multiple rifles, a full-length die set is the workhorse tool that'll outlast several barrels on the same gun.

The full-length sizing die does the heavy lifting: it bumps the shoulder back to spec (adjustable via die position), sizes the case body so rounds chamber cleanly, and removes the spent primer in one pass. The expander ball sizes the neck to proper bullet tension. Just remember that cases need lubrication before running through the sizing die. The seating die then seats bullets consistently and includes a built-in crimp ring if you want to crimp the case neck to the bullet—easily toggled on or off by adjusting die height in the press.

RCBS dies are built for precision and longevity. New reloaders benefit most by learning full-length die setup before exploring neck-sizing or other specialized techniques. If you're already running a 300 Win Mag and want to consolidate component costs or reload for multiple rifles, this set gives you the flexibility to work with both full-length and neck-sized brass.

Key Features

• Full-length sizing die with adjustable shoulder bump and integrated primer removal
• Expander ball for precise neck sizing and bullet tension
• Seating die with optional crimp ring (adjustable via die position)
• Matched 2-die set engineered for 300 Winchester Magnum
• Durable construction rated for multiple barrel lifecycles
• Ideal for new reloaders and experienced handloaders alike

Specifications

Brand	RCBS
Model	15301
Cartridge	300 Winchester Magnum
Type	Full-Length 2-Die Set
Dies Included	Full-length sizing die, seating die
Case Type	Bottleneck rifle

Frequently Asked Questions

Do I need to lubricate cases before using the full-length sizing die?

Yes. Cases must be lubricated before running them through the full-length sizing die to ensure smooth operation and prevent damage.

Can I use this die set with both full-length and neck-sized brass?

The seating die will seat bullets in both full-length sized and neck-sized cases. The full-length sizing die itself performs full-length sizing; it can't perform neck-only sizing.

Does this set include a crimp feature?

Yes. The seating die includes a built-in crimp ring. You can crimp or skip the crimp by adjusting the die height in your press.

Is a full-length die set good for someone new to reloading?

Absolutely. RCBS recommends that new reloaders start with a full-length die set to learn proper setup and technique before exploring other reloading die types.