RCBS 300 Win Mag Small Base Die Set - Precision Reloading Dies
$58.69
- Caliber-Gauge:
- 300 Winchester Magnum
The RCBS 300 Win Mag Small Base Die Set is purpose-built for reloaders working with tight-chambered semi-automatic, pump, and lever-action rifles. Where standard dies may not resize cases enough to chamber reliably in firearms with minimal headspace tolerance, this two-die set steps in with specialized geometry that brings cases below SAAMI minimums—reducing both shoulder and body dimensions by a few thousandths of an inch. That precision fit translates to consistent cycling and reliable feeding in firearms that demand it.
The set includes a Small Base Sizer that also serves as your decapping tool, removing spent primers in the same stroke as resizing. This dual function saves a separate step and keeps your reloading bench workflow efficient. The companion Regular Seater Die features a built-in roll crimper that secures your bullet while seating it, creating a tight, stable load in one operation. If you prefer to seat bullets without crimping—say, for match-grade loads where you'll crimp separately or not at all—simply back off the die until the crimp ring no longer contacts the case mouth.
Built on RCBS's reputation for tight tolerances and consistent performance, this die set gives you the exact tool you need for 300 Win Mag loads in guns that run hot or tight. Whether you're handloading for a modern sporting rifle or a bolt-action with demanding chamber specs, the Small Base geometry ensures your brass fits and functions flawlessly.
Key Features
- Two-die set designed for tight-chambered semi-automatic, pump, and lever-action rifles
- Small Base Sizer resizes cases below SAAMI specifications for reliable fit in firearms with minimal headspace tolerance
- Integrated decapping function removes primers during the resize stroke
- Seater Die with built-in roll crimper secures bullets while seating
- Crimp function can be disabled by unscrewing the die for bullet-seating-only operation
Specifications
| Caliber | 300 Winchester Magnum |
| Type | Two-die set (Sizer/Decapper, Seater with Crimp) |
| Sizer Style | Small Base |
| Case Type | Bottleneck |
| Application | Semi-automatic, pump, and lever-action rifles with tight chambers |
Frequently Asked Questions
What's the difference between a Small Base die and a standard die?
A Small Base die resizes cases more aggressively, bringing them below SAAMI minimum dimensions. This is essential for semi-automatic and lever-action rifles with tight chamber tolerances, ensuring reliable feeding and consistent headspace. Standard dies resize to SAAMI specs, which may not be tight enough for some action types.
Can I reload 300 Win Mag ammunition for bolt-action rifles with this set?
Yes. While this set is specifically engineered for tight-chambered semi-automatic, pump, and lever-action rifles, the Small Base sizing will work for bolt-action rifles as well. Bolt guns typically have looser tolerances, so the aggressive sizing is unnecessary but not harmful.
Does the set come with both a decapping tool and a primer pocket cleaning tool?
The Small Base Sizer includes a decapping pin that removes spent primers during the resizing stroke. Based on the included components, the set contains the Sizer/Decapper and Seater Die only.
How do I use the die without the roll crimp?
Simply unscrew the Seater Die until the crimp ring no longer engages the case mouth. You can then seat bullets without crimping, which is useful if you prefer to crimp separately, use a different crimp method, or load match-grade ammunition where crimping is not desired.
