Peterson Unprimed Cases - 300 Rum 50Pack 10Bx/Cs
Peterson Unprimed Cases for the 300 Rum deliver the consistency that serious handloaders demand. Built on Peterson Cartridge's match-grade manufacturing standard, these rifle cases are engineered for shooters who prioritize accuracy and reliability from the ground up. Whether you're loading precision rifle rounds for long-range hunting or competition shooting, Peterson's small-batch production process ensures each case meets exacting tolerances—so your focus stays on technique, not sorting defects.
The 300 Rum is a powerful belted magnum known for flat trajectory and hard-hitting performance downrange. Peterson's unprimed cases give you a clean slate to build loads tailored to your rifle and shooting discipline. With 50 cases per box and 10 boxes per case, you'll have a solid supply to develop loads and maintain consistency across multiple range sessions or hunting seasons.
Peterson's reputation rests on the idea that match-grade shouldn't be an exception—it's the floor. Their quality control process screens for uniformity in capacity, wall thickness, and concentricity, reducing variables that can drift your groups or create pressure anomalies. If you're accustomed to commercial brass and ready to step up to cases engineered for tight tolerances, Peterson unprimed cases are a worthwhile investment in your reloading bench.
Key Features
- Match-grade manufacturing standard across all production
- Small-batch production for consistent lot uniformity
- Unprimed format—ready for your primer of choice
- 50 cases per box; 10 boxes per case (500 cases total)
- Engineered for precision rifle and competition loading
Specifications
| Cartridge | 300 Rum |
| Condition | Unprimed |
| Cases per Box | 50 |
| Boxes per Case | 10 |
| Total Cases | 500 |
| Manufacturer | Peterson Cartridge |
Frequently Asked Questions
Are these cases new or once-fired?
These are new, unprimed brass—straight from Peterson's manufacturing process with no prior use.
What does unprimed mean, and what do I need to do with them?
Unprimed means the cases come without primers installed. You'll seat your chosen primer (small or large rifle) during your reloading process, giving you full control over the primer selection for your specific load.
What is Peterson's match-grade standard?
Peterson manufactures to strict tolerances for case capacity, wall thickness, and concentricity to ensure consistency from case to case. This reduces variables that can affect accuracy and helps you maintain tighter groups and more predictable ballistics.
Is the 300 Rum suitable for hunting and long-range shooting?
Yes. The 300 Rum is a belted magnum cartridge known for flat trajectory and effective downrange energy, making it popular for both long-range hunting and precision rifle competition. Peterson's cases are engineered to support accuracy-focused handloading across these disciplines.

