SilencerCo 9mm 3-Lug Barrel Adapter - 1/2x28 Thread Pitch, High-Strength Stainless Steel Construction, Precision HK-Spec 3-Lug Profile, Matte Black Finish - AC2604 / 816413025154
Product Description
Adapting 9mm Pistol Caliber Carbines (PCCs) and submachine guns for quick-detach suppressor mounting requires absolute concentricity to eliminate costly baffle strikes. Threading suppressors directly onto 1/2x28 barrel threads often leads to carbon locking, unthreading during rapid fire, and slow, cumbersome mounting on your bench. The **SilencerCo® 9mm 3-Lug Barrel Adapter (AC2604 / 816413025154)** flatlines these suppressor attachment bottlenecks, converting standard 1/2x28 threaded barrels into a fast, reliable **HK-spec 3-lug mounting system**.
Precision-engineered in West Valley City, Utah by SilencerCo, the AC2604 3-lug adapter is CNC-machined from high-strength **stainless steel** and finished in a durable, non-reflective **matte black oxide finish**. Built to exact HK MP5 3-lug dimensions, it provides a positive push-and-twist interface for 9mm suppressors equipped with a 3-lug mount housing (such as the SilencerCo Omega 9K, Octane 9, or Switchback). The internal 1/2x28 threads seat firmly against the barrel shoulder, ensuring perfect bore alignment and repeatable point-of-impact (POI) retention straight from your armorer bench.
Engineered to thread natively onto all 1/2x28 threaded 9mm barrels (AR-9, CZ Scorpion, SIG MPX, Ruger PC Carbine), this factory-calibrated muzzle adapter guarantees fast, rock-solid suppressor mounting directly from your workspace bench.
*Armorer Bench Notes & Real-World 3-Lug Staging Guidance: The SilencerCo AC2604 adapter arrives workspace ready as a precision-machined single-piece muzzle device. CALIBER & THREAD PITCH COMPATIBILITY MATRIX: Engineered specifically for **9x19mm / 9mm Luger** barrels featuring standard **1/2x28 TPI (Threads Per Inch)**. *Suppressor Fitment:* Interfaces natively with all standard **HK-spec 3-lug suppressor mounts** (SilencerCo AC2447 9mm 3-Lug Mount, Rugged, Dead Air, B&T). Armorer Workbench Custom Staging Sequence: 1. Visually and physically confirm your host firearm is completely clear of live ammunition, the magazine is removed, and the chamber is checked safe and empty. 2. Thoroughly clean the barrel's 1/2x28 muzzle threads and shoulder to remove carbon buildup and grease on your bench. 3. Apply a drop of high-temperature thread locker (e.g., Rocksett) to the male barrel threads. 4. Thread the AC2604 adapter onto the barrel until it seats squarely against the barrel shoulder. 5. Torque the adapter to **20 to 25 foot-pounds** using a calibrated wrench across the wrench flats. 6. Verify bore alignment using a 9mm alignment rod before mounting your 3-lug suppressor and rolling downrange.*
Key Features
- Instant Push-and-Twist 3-Lug Attachment: Converts standard 1/2x28 threaded barrels into a rapid-detach HK-spec 3-lug mounting hub.
- Precision CNC-Machined Stainless Steel: Cut from solid stainless steel bar stock for extreme thermal resistance and long-term durability under full-auto firing schedules.
- Concentric Bore Alignment: Factory-calibrated tolerances guarantee perfect alignment with the barrel bore, preventing suppressors from loosening or baffle strikes.
- Durable Matte Black Protective Finish: Heat and chemical-resistant black finish shields the steel adapter from harsh carbon fouling and environmental moisture.
- Standard 1/2x28 Thread Pitch: Fits the vast majority of 9mm PCCs, AR-9s, and subgun barrels on the market today.
- Integrated Wrench Flats: Machined side wrench flats allow clean, slip-free torque application during bench installation.
Product Specifications
- Brand: SilencerCo® (West Valley City, UT / Made in the USA)
- Model Line: Suppressor Muzzle Adapters & 3-Lug Series
- MPN/SKU Code: AC2604 (SilencerCo 3-Lug Adapter 9mm 1/2x28 SKU)
- UPC Code Profile: 816413025154
- Thread Pitch Interface: 1/2x28 TPI (Threads Per Inch) Female Threads
- Caliber Standardization: 9x19mm Luger / 9mm NATO (Max Bore Diameter)
- Mounting Interface Profile: HK-Spec 3-Lug Male Quick-Detach Lug Pattern
- Structural Material Base: Precision CNC-Machined High-Strength Stainless Steel
- Exterior Finish Dressing: Matte Black Protective Heat-Resistant Coating
- Installation Tool Interface: Integrated Precision Parallel Wrench Flats
- Full Kit Component Checklist: 1x SilencerCo 9mm 3-Lug 1/2x28 Barrel Adapter
- Packaging Format Class: Factory Original Sealed SilencerCo Header Display Bag
- Product Type Category: Firearms Accessories / Suppressor Muzzle Devices & Adapters
- Net Component Mass: ~1.80 Ounces (~51.0 Grams Stainless Steel Adapter Mass)
- Global Quality Certifications: Formulated to Rigid US Suppressor Performance & Duty Metrics
- Warranty Tracking Protection: Fully Backed by SilencerCo Factory Limited Lifetime Warranty
