8.6 Blackout Ballistics: Velocity, Energy & Trajectory Data

8.6 Blackout Ballistics: Velocity, Energy, and Performance Data

The 8.6 Blackout (.338 caliber) was engineered to maximize both subsonic and supersonic performance from the AR-10 platform. This page covers the real-world ballistics data for every load in Gorilla Ammunition’s 8.6 Blackout lineup — including muzzle velocity, muzzle energy, and barrel-length considerations.

8.6 Blackout Subsonic Ballistics

Subsonic 8.6 Blackout loads travel below 1,125 fps — the speed of sound — which eliminates the supersonic crack and allows a suppressor to reduce the report to safe hearing levels. The key advantage of the 8.6 Blackout over competing subsonic cartridges is raw energy: the .338 bore carries dramatically more energy at subsonic speeds than .300 Blackout or other suppressor cartridges.

Load	Bullet Weight	Barrel Length	Muzzle Velocity	Muzzle Energy
Gorilla Silverback 285gr Fracturing Subsonic	285gr	16″	~1,060 fps	~712 ft-lbs
Gorilla Silverback 285gr Fracturing Subsonic	285gr	12″	~1,020 fps	~659 ft-lbs
Gorilla Silverback 285gr Fracturing Subsonic	285gr	8″	~980 fps	~608 ft-lbs
300gr Sierra MatchKing Subsonic (16″ load)	300gr	16″	~1,040 fps	~720 ft-lbs
300gr Sierra MatchKing Subsonic (8″/12″ load)	300gr	8″–12″	~990 fps	~653 ft-lbs
300gr Berger Hybrid Subsonic (Bolt Action)	300gr	16″+	~1,080 fps	~777 ft-lbs
342gr Pork Shredder Expanding Subsonic	342gr	16″	~1,040 fps	~822 ft-lbs

8.6 Blackout Supersonic Ballistics

In supersonic configuration, the 8.6 Blackout launches 210gr projectiles at velocities that rival or exceed .308 Winchester in energy — from a semi-automatic AR-10 platform. The 210gr Barnes TSX is Gorilla Ammunition’s flagship supersonic hunting load for the 8.6 Blackout.

Load	Bullet Weight	Barrel Length	Muzzle Velocity	Muzzle Energy
210gr Barnes TSX Supersonic	210gr	16″	~2,400 fps	~2,685 ft-lbs
210gr Barnes TSX Supersonic	210gr	12″	~2,250 fps	~2,362 ft-lbs

Why Barrel Length Matters for 8.6 Blackout

Because the 8.6 Blackout was developed specifically to optimize performance at different barrel lengths, Gorilla Ammunition produces barrel-specific loads for subsonic applications. A 300gr projectile loaded to run truly subsonic in a 16″ barrel will be supersonic in an 8″ barrel — a critical distinction for suppressor performance and sound signature.

8″ barrel loads — Tuned for compact suppressed builds. Lower powder charge ensures true subsonic flight.
12″ barrel loads — The sweet spot for most suppressed 8.6 Blackout builds. True subsonic with more velocity than an 8″ load.
16″ barrel loads — Maximum velocity for semi-auto use. True subsonic at higher powder charge.
Bolt-action loads — No cycling requirement allows heavier powder charges for maximum energy at subsonic speeds.

How Does 8.6 Blackout Compare to Other Subsonic Cartridges?

Cartridge	Subsonic Bullet	Muzzle Energy	Platform
8.6 Blackout	285–342gr	600–820 ft-lbs	AR-10 / GF-10
.300 Blackout	200–220gr	450–500 ft-lbs	AR-15
.45-70 Govt (subsonic)	400–500gr	700–900 ft-lbs	Lever action
9mm (subsonic)	147gr	~175 ft-lbs	Pistol / PCC

Shop 8.6 Blackout Ammo

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