Sig Sauer MPX & PCC Barrel Taper Cap - 1/2x28 Thread Shoulder Conversion Adapter, Taper-Lok to 90-Degree Flat Shoulder Interface, Heat-Treated Alloy Steel Construction, Anodized Black Finish - 1811268-R / 798681608560
Product Description
Mounting aftermarket suppressors, muzzle brakes, or flash hiders on a Sig Sauer Pistol Caliber Carbine (PCC) or MPX platform requires a squared, flat barrel shoulder for true 90-degree alignment. Sig Sauer barrels feature a proprietary 25-degree Taper-Lok shoulder design engineered for native Sig muzzle devices. Attempting to seat standard flat-backed muzzle devices, timing shims, or crush washers directly onto a tapered barrel shoulder causes severe misalignment, erratic point-of-impact shifts, and catastrophic baffle strikes. The **Sig Sauer® PCC Barrel Taper Cap (1811268-R / 798681608560)** solves these mounting bottlenecks, converting your tapered muzzle shoulder into a traditional 90-degree flat shoulder.
Proudly engineered and precision-machined in the United States by Sig Sauer, this factory OEM adapter is carved from high-tensile **heat-treated alloy steel** finished in a corrosion-resistant anodized matte black dressing. Designed to slip directly over standard **1/2x28 threaded PCC barrels**—including Sig Sauer MPX models, copperhead platforms, and 9mm PCC carbines—the interior profile mirrors Sig's exact 25-degree taper, while the exterior presents a parallel 90-degree face. This adapter allows armorers and shooters to safely install non-tapered muzzle devices, suppressor QD mounts, or timing shims with zero thread binding or concentricity issues straight from their armorer bench.
Engineered to slide over standard 1/2x28 threaded Sig PCC muzzles, this factory-calibrated taper cap guarantees absolute 90-degree shoulder alignment directly from your workspace bench.
*Armorer Bench Notes & Real-World Taper Cap Staging Guidance: The Sig Sauer 1811268-R Taper Cap arrives workspace ready as a precision-machined steel adapter ring. SIG TAPER-LOK BARREL CONVERSION MATRIX: This adapter is engineered natively, strictly, and dimensionally to slide over **Sig Sauer 9mm PCC / MPX barrels equipped with 1/2x28 thread patterns and a 25-degree tapered shoulder**. *Muzzle Device Alignment Checklist:* This taper cap is required whenever installing **flat-backed non-Sig muzzle devices, suppressor alignment shims, crush washers, or direct-thread suppressors** that require a traditional 90-degree square shoulder. Armorer Workbench Custom Staging Sequence: 1. Visually and physically confirm your host PCC firearm is completely clear of live ammunition, the magazine is removed, and the chamber is checked safe and empty. 2. Remove any existing muzzle device or thread protector from the 1/2x28 muzzle threads. 3. Thoroughly clean the barrel threads and tapered shoulder using isopropyl alcohol and a shop towel to clear carbon fouling or field grease. 4. Orient the Sig Taper Cap so the internal 25-degree beveled side faces rearward toward the receiver. 5. Slide the cap down over the threads until it seats flush and snug against the barrel's tapered shoulder. 6. Install your chosen timing shims, crush washer, or flat-backed muzzle device against the newly created 90-degree flat face, torque to manufacturer specs, and verify bore alignment using a suppressor alignment rod before rolling downrange.*
Key Features
- Converts Tapered Muzzle to 90° Shoulder: Adapts Sig Sauer's proprietary 25-degree Taper-Lok barrel shoulder into a traditional 90-degree flat shoulder for universal muzzle device compatibility.
- Prevents Suppressor Baffle Strikes: Provides a true square index face for direct-thread suppressors, QD mounts, and alignment shims, eliminating strike risks caused by canted seating.
- Precision-Machined Heat-Treated Steel: Constructed from ultra-durable alloy steel to withstand extreme muzzle blast heat, gas erosion, and high torque loads.
- Fits Standard 1/2x28 Thread Patterns: Dimensioned specifically to slide over standard 9mm / .223 / 5.56 1/2x28 barrel threads found across Sig PCC and MPX platforms.
- Corrosion-Resistant Anodized Finish: Treated with a tough, non-reflective matte black finish that resists rust, powder residue, and chemical bore solvents.
- Factory OEM Sig Sauer Component: Precision-milled to exact Sig factory specifications for guaranteed fitment and seamless barrel integration.
Product Specifications
- Brand: Sig Sauer® (Newington, NH / Made in the USA)
- Model Line: Taper Cap Adapter Series - Muzzle Conversion Accessories
- MPN/SKU Code: 1811268-R (PCC Taper Cap 1/2x28 Black Standard SKU)
- UPC Code Profile: 798681608560
- Muzzle Thread Standard: Fits 1/2x28 Thread Pitch Profiles
- Barrel Taper Profile: Converts 25-Degree Taper-Lok Shoulder to 90-Degree Flat Shoulder
- Host Firearm Compatibility: Sig Sauer MPX, PCC 9mm Barrels, MCX / M400 1/2x28 Barrels
- Structural Material Base: Precision CNC-Machined Heat-Treated Alloy Steel
- Exterior Finish Dressing: Corrosion-Resistant Matte Black Anodized Armor Shield
- Full Kit Component Checklist: 1x Sig Sauer 1811268-R PCC Barrel Taper Cap
- Packaging Format Class: Factory Original Sealed Sig Sauer Branded Poly Bag / Display Header
- Product Type Category: Firearm Components / Barrel Accessories & Thread Adapters
- Overall Physical Outer Diameter: ~0.75 Inches (~19.0 mm Outer Rim Profile)
- Net Component Mass: ~0.30 Ounces (~8.5 Grams Ultra-Lightweight Steel Ring)
- Global Quality Certifications: Built strictly to OEM Factory Specifications & Quality Metrics
- Warranty Tracking Protection: Fully Backed by Sig Sauer Factory Limited Warranty
