Hornady Unprimed Brass Rifle Cases, .300 Blackout, 4000ct

Hornady Unprimed Brass Rifle Cartridge Cases in .300 Blackout (Hornady part no. 86751B) give high-volume handloaders a bulk 4,000-count box of brass built to Hornady’s tight manufacturing tolerances. Hornady takes extra time and care producing smaller lots of brass to meet strict quality standards, resulting in excellent uniformity in wall thickness, weight, and internal capacity from case to case. That consistency is what lets serious .300 Blackout reloaders, from suppressed pistol-caliber carbines to subsonic hunting loads, build accurate, repeatable ammunition batch after batch.

Key Specifications

• Chambered for .300 Blackout, ready for full-length or neck sizing straight out of the box.
• Sold in a bulk 4,000-count box, suited to high-volume handloaders and small shops.
• Manufactured with tight wall concentricity for consistent bullet seating and case-to-case uniformity.
• Every case is run through a pressure calibration test to confirm uniform case expansion during firing.
• Ships unprimed, giving handloaders full control over primer selection for their specific load.
• Ships at approximately 47.2 lb per case, worth planning for on the receiving end.

Frequently Asked Questions

Does this brass come primed? No, this is unprimed brass, so you’ll select and seat your own primers as part of your load development.

Why does case concentricity matter? Tight wall concentricity keeps bullet seating consistent from case to case, which directly improves accuracy and reduces velocity spread.

What does the pressure calibration test check? Hornady runs its cases through a pressure calibration test to confirm they expand uniformly when fired, which supports consistent chamber and bullet seating.

Buy the Hornady Unprimed Brass Rifle Cases, .300 Blackout, 4000ct

Build your best .300 Blackout loads on a foundation of consistent, quality-tested brass. Shop more from Hornady in our reloading brass selection and order from our Lubbock, Texas gun shop for fast, direct shipping.