Rugged Suppressor OA004 Obsidian 3 Lug Adapter Black 13.5x1 LH TPI for 9mm Luger HK

The Rugged Suppressor OA004 Obsidian 3 Lug Adapter is a precision-engineered muzzle device designed to convert your 9mm Luger HK-threaded barrel for use with the Obsidian 3 Lug suppressor mount system. If you're running an HK-pattern host gun and want to transition to modular suppressor mounting, this adapter bridges that gap cleanly—no re-barreling required. It's a straightforward, durable solution for shooters who need reliable mechanical connection between their threaded muzzle and a modern quick-detach suppressor system.

Built to Rugged Suppressor's exacting standards, the OA004 combines precise machining with robust materials that handle the pressures and vibration cycles of suppressed fire without premature wear or loosening. The left-hand 13.5x1 thread pitch is specific to HK-platform firearms, so verify your barrel before ordering—this is a direct fit for that specification only. Once installed, it provides a solid mounting interface that keeps your suppressor locked in place across rapid strings of fire and handling cycles.

Weighing just 0.13 lbs, the adapter adds minimal mass to your muzzle. The black finish matches most modern suppressors and tactical setups. Whether you're outfitting a suppressed 9mm pistol-caliber carbine, a short-barreled rifle, or any HK-threaded 9mm host, this adapter is a no-fuss way to access Rugged's modular suppressor ecosystem without permanent modifications to your barrel.

Key Features

• Precision-machined for reliable mechanical fit and zero-point repeatability
• Durable construction handles sustained suppressed fire without degradation
• Lightweight design—minimal added muzzle mass
• Works with the Obsidian 3 Lug Mount suppressor system
• Black anodized finish

Specifications

Frequently Asked Questions

Will this adapter work on my HK 9mm barrel?

Yes, but only if your barrel is threaded 13.5x1 LH (left-hand). This is the standard HK-pattern thread pitch. Double-check your barrel specs before purchasing—using the wrong thread pitch can result in a dangerous, non-functional installation.

What suppressor does this adapter work with?

The OA004 is designed to interface with the Rugged Suppressor Obsidian 3 Lug Mount system. Verify suppressor compatibility before ordering.

Can I use this on an AR15 or other platform besides HK?

No. This adapter is specific to barrels threaded in the HK 13.5x1 LH pattern. Standard AR15 barrels use different threads (usually .578x28 or .625x24 RH) and are not compatible.

Is this a permanent installation?

The adapter screws onto your barrel and can be removed, but once tightened, it should remain secure. Do not over-torque; hand-tighten plus a quarter turn is typical. Always verify a tight fit before firing.