The Q Boombox 12-inch SBR in 8.6 Blackout (brand part no. BOOMBOX-86-12IN-SBR) gives the platform more barrel without losing what makes the Boombox work. Q built it around suppressed shooting, with a fast 1:3 twist, an adjustable gas system and SR-25 magazine compatibility. This is the longer SBR option for shooters who want more velocity and room to work, while keeping the compact, hard-hitting nature of 8.6 Blackout. It sits between the ultra-compact 8-inch model and a full-size rifle. A clear anodized finish and a Cherry Bomb XL muzzle device complete a short, maneuverable suppressor host.

Key Specifications

• The caliber is 8.6 Blackout, designed as the platform cartridge from day one.
• The barrel is 12 inches, more length than the 8-inch model for added velocity.
• The twist rate is 1:3, a fast twist for heavy 8.6 BLK projectiles.
• An adjustable gas system lets you tune the rifle around your suppressor and ammunition.
• Magazines are SR-25 pattern, a familiar and widely available standard.
• The configuration is an SBR, the stocked version of the 12-inch Boombox.
• The finish is clear anodize, a durable aluminum surface treatment.
• The muzzle device is a Cherry Bomb XL on an M18x1.5 thread.
• Weight is 5 pounds 8 ounces, light for a rifle-caliber SBR.
• Overall length is 31.25 inches extended and 26.75 inches collapsed, as listed by Q.

Frequently Asked Questions

Do I need ATF approval to buy this? No. As of October 9, 2026, ATF no longer requires Form 4 approval, registration or a tax stamp for short-barreled rifles. It transfers on a Form 4473 with a background check through a Class 3 (SOT) dealer. State and local laws still apply. Taking an SBR across state lines still requires an approved ATF Form 5320.20.

How is it different from the Boombox pistol? This is the stocked SBR version. Q also sells brace-equipped pistol versions in 8-inch and 12-inch barrel lengths.

What magazines and muzzle device does it use? It uses SR-25 pattern magazines and a Cherry Bomb XL muzzle device on an M18x1.5 thread.

Buy the Q Boombox 12-Inch SBR, 8.6 Blackout

As of October 9, 2026, this short-barreled rifle transfers on a Form 4473 with a background check at your Class 3 (SOT) dealer, with no Form 4 or tax stamp; state and local laws still apply. Order through Q LLC‘s short-barrel rifle lineup and our Lubbock, Texas team will handle the transfer.