Starline 300 Blackout Unprimed Rifle Brass, 100ct

Starline’s .300 Blackout Unprimed Rifle Brass (brand part no. 300BLKEUP100) is based on a shortened 5.56x45mm case necked to .30 caliber, letting AR-15 platform shooters go from 5.56 to .300 Blackout with just a barrel change. The cartridge’s main purpose is subsonic performance in suppressed firearms, and it’s increasingly offered in bolt-action and single-shot rifles too. This case measures 1.356 in. to 1.360 in. in length with a small primer pocket, and Starline packages it 100 to a bag.

Key Specifications

• Chambered for .300 Blackout, built on a shortened, necked-down 5.56x45mm case.
• Measures 1.356 in. to 1.360 in. in case length.
• Uses a small primer pocket.
• Suited to AR-15 platform rifles and pistols, as well as bolt-action and single-shot rifles.
• Packaged 100 cases per bag.

Frequently Asked Questions

What platforms is this brass suited for? AR-15 platform rifles and pistols, plus a growing number of bolt-action and single-shot rifles.

What is .300 Blackout typically used for? It’s popular for subsonic-velocity shooting, especially with suppressed firearms.

What primer pocket size does it use? Small primer pocket.

Buy the Starline 300 Blackout Unprimed Rifle Brass

Order Starline .300 Blackout Brass from our Lubbock, Texas gun shop for fast, direct shipping. It’s the dependable case behind one of the most versatile AR-15 cartridges available. Browse more of our reloading brass selection while you shop.