Rugged Suppressor Obsidian 3 Lug Adapter — Black — 13.5×1 LH tpi — for 9mm Luger / HK (Model OA004, UPC: 859383006716)
Make your Rugged Suppressors Obsidian 3 or other compatible 3-lug direct-mount cans work with a wider range of host pistols using the Rugged Suppressor Obsidian 3 Lug Adapter (Model OA004). Finished in matte black and threaded 13.5×1 left-hand, this precision-machined adapter lets shooters mount a 3-lug suppressor to HK-pattern pistols and 9mm Luger handguns that accept that thread standard — giving you stable, repeatable alignment, secure lockup, and minimal point-of-impact shift when attaching a can or quick-detach muzzle device.
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Product Overview
The OA004 lug adapter is engineered as a hardened, repeatable interface between your pistol’s threaded muzzle and the Obsidian 3 (or any compatible 3-lug suppressor) mounting system. Crafted to precise tolerances, the adapter ensures concentric alignment with the bore, resists loosening under recoil, and preserves the user’s zero when mounting and dismounting the suppressor. The left-hand 13.5×1 thread pattern is commonly used on several HK and other European/aftermarket barrels — verify your barrel’s thread spec before purchase.
Key Features & Benefits
Model: OA004
UPC: 859383006716
Threading: 13.5×1 LH (left-hand) tpi — fits barrels cut to this thread standard.
Compatibility: Designed for 9mm Luger platforms and HK-pattern pistols that use the 13.5×1 LH thread; pairs with Rugged Obsidian 3 and other 3-lug suppressors.
Finish: Matte black — low-glare, corrosion-resistant coating to match dark slides and barrels.
Material: High-strength, heat-treated steel (precision machined) for durability under repeated use and thermal stress.
Repeatable Indexing: Engineered to index consistently for minimal POI shift when removing and remounting a suppressor.
Secure Lockup: Positive 3-lug engagement for a tight, wobble-free mount that resists rotation and loosening.
Low-Profile: Slim design keeps overall length and bore offset to a minimum for better holster/handling compatibility.
Easy Installation: Threads on like a standard muzzle device; lugs engage with the suppressor or mount and lock quickly.
Why This Adapter Matters
A dedicated lug adapter lets you convert a threaded 9mm/HK muzzle to accept quick-detach 3-lug suppressors without requiring permanent modifications to the suppressor or the host firearm. Rugged’s OA004 preserves concentricity and repeatability — two qualities that matter for accuracy and reliability when using cans on defensive, duty, or range pistols.
Compatibility & Fitment Notes
Intended Platform: 9mm Luger pistols and HK-pattern pistols that have barrels threaded 13.5×1 LH.
Suppressor Fit: Made for use with Rugged Obsidian 3 suppressors and other manufacturer 3-lug devices — confirm your suppressor’s lug geometry and engagement depth before use.
Thread Confirmation: Always verify barrel threading (13.5×1 LH) prior to purchase. Using the wrong thread pitch or hand (RH vs LH) can damage barrel threads and create unsafe mounting.
Not Universal: Does not adapt to other thread pitches or lug patterns without appropriate thread adapters or host-specific mounts.
Installation Guide (Quick Steps)
Safety First: Ensure firearm is completely unloaded; remove magazine and visually/physically check the chamber.
Thread-On Adapter: Screw the OA004 onto the barrel’s external threads by hand until finger-tight. The left-hand thread will turn counter-clockwise to tighten (confirm direction before full install).
Torque & Timing: Using a properly sized wrench or armorer tool, torque to the manufacturer’s recommended spec. Index the adapter so the 3-lug recess aligns for correct engagement with the Obsidian 3 suppressor. If using a crush washer or shims, follow the barrel or adapter instructions for proper timing.
Mount Suppressor: Align the suppressor’s 3-lug recess with the adapter and rotate to lock. Confirm secure engagement and that the suppressor is concentric and does not contact the slide or frame.
Function Check: Conduct a dry-fire check for any interference. Then perform a controlled live-fire verification at the range to confirm reliable cycling, no baffle strikes, and acceptable point-of-impact shift.
Maintenance & Care
Inspect Threads: Regularly inspect both barrel and adapter threads for galling or damage. Replace if threads show significant wear.
Keep Clean: After range sessions, remove carbon and lead buildup from the adapter interior and lugs using appropriate brushes and solvent. Dry thoroughly to prevent corrosion.
Anti-Seize: Apply a small amount of anti-seize or high-temp thread compound recommended by the manufacturer if you frequently install/remove the adapter to protect threads and ease future removal.
Torque Check: Re-torque after the first 30–50 rounds and periodically thereafter to ensure the adapter remains properly seated.
Technical Specifications (At-a-Glance)
Model: OA004
UPC: 859383006716
Thread: 13.5×1 LH tpi (left-hand)
Material: Heat-treated steel (precision machined)
Finish: Matte black corrosion-resistant coating
Intended Caliber: 9mm Luger (primary) — fits HK-pattern pistols with matching threads
Mount Style: 3-lug adapter for Rugged Obsidian 3 and compatible suppressors
Safety & Legal Considerations
Legal Reminder: Suppressors, adapters, and related muzzle devices are regulated in many jurisdictions. Ensure compliance with local, state, and federal laws before purchasing or possessing suppressor components or adapters. In jurisdictions where suppressors are restricted, adapters alone may still be subject to regulation. Consult a licensed dealer or legal counsel if unsure.
Professional Help: If you are uncertain about proper torque, timing, or compatibility, consult a qualified armorer or gunsmith. Improper installation may cause baffle strikes, thread damage, or unsafe firearm operation.
Final Thoughts
The Rugged Suppressor Obsidian 3 Lug Adapter (OA004) is a compact, precision-made solution for shooters who want to pair Rugged’s Obsidian 3 (or compatible 3-lug suppressors) with 9mm or HK-pattern pistols threaded 13.5×1 LH. With hardened construction, repeatable indexing, and a low-profile matte black finish, the OA004 makes adding a quick-detach suppressor a secure, accurate, and user-friendly upgrade to your pistol setup.
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