Premium .300 Blackout Brass for Sale — Once-Fired & Processed Options

Reload your own .300 AAC Blackout brass with confidence using Diamond K Brass, your trusted source for once-fired and processed reloading brass. Each case is inspected, tumble-polished, and prepared for top-tier performance — ideal for target shooters, reloaders, and hunters who demand precision and reliability.

Why Choose Diamond K Brass .300 BLK Brass

Our .300 AAC Blackout brass delivers exceptional consistency and long-lasting performance. Unlike other suppliers, we hand-sort and clean every lot to remove debris, ensuring smooth chambering and dependable reloads. Whether you’re running a suppressed setup or fine-tuning your subsonic loads, Diamond K Brass gives you the edge in accuracy and quality.

Once-Fired & Processed .300 BLK Brass Options

We offer two convenient options for reloaders:

• Once-Fired .300 Blackout Brass: Cleaned, polished, and ready for resizing and depriming.

• Processed .300 BLK Brass: Fully prepped and ready to load — resized, trimmed, and de-primed for your convenience.

Our brass is available in 100, 500, and 1,000-count packages, perfect for both small reloaders and bulk buyers.

Affordable Quality You Can Trust

With ammunition costs continuing to rise, reloading with once-fired brass helps you save significantly without sacrificing performance. Our customers rely on us for premium reloading components and exceptional service — we deliver exactly what we advertise, every time.

Fast Shipping & Customer Satisfaction

We pride ourselves on fast order processing — most orders ship within one business day. Every shipment is securely packed, and we include 2% extra brass in each order to ensure complete satisfaction.

What Our Customers Say

“Excellent brass quality and consistent sizing. Diamond K Brass is my go-to for all my reloading needs!”

Order Your .300 Blackout Brass Today

Whether you’re loading subsonic rounds for your AR platform or preparing bulk brass for future range sessions, Diamond K Brass has you covered. Shop once-fired or processed .300 BLK brass online and experience unmatched quality and service.