Nosler Custom Brass for the .300 Blackout (Nosler part no. 45123) gives handloaders new, unprimed cases that are fully prepped and ready to load right out of the box. Each lot is weight-sorted for consistent case capacity and, by extension, consistent handloaded velocities, while the mouths and flash holes come pre-chamfered and deburred to save prep time at the bench. Every piece in a batch offers matching trimmed length and neck wall thickness, giving serious .300 Blackout handloaders a repeatable starting point for their loads.

Key Specifications

• Chambered for .300 Blackout, one of the most popular modern AR-platform cartridges.
• Cases are weight-sorted, ensuring consistent internal capacity from case to case.
• Mouths and flash holes are pre-chamfered and deburred, saving handloaders a prep step.
• Delivered with matching trimmed length and neck wall thickness across the lot.
• Packaged 50 cases per pack, sized for a solid handloading batch.

Frequently Asked Questions

Are these cases primed? No, this is new, unprimed brass ready for priming and loading.

What prep work is already done? The mouths and flash holes are pre-chamfered and deburred, and the cases are weight-sorted for consistency.

How many cases come in a pack? Each pack contains 50 cases.

Buy the Nosler Custom Brass .300 Blackout Cases

Nosler builds Custom Brass to give handloaders a consistent, ready-to-load starting point. Shop our reloading brass selection and order today for fast, insured shipping from our Lubbock, Texas shop.