CMC Triggers AR-15 8-Position Extended Buffer Tube Assembly Kit – A5 Length (8P-A5), Black - SKU: 83626 - UPC: 810169560686
Product Description
The CMC Triggers 8-Position Extended Buffer Tube Assembly Kit (83626) brings the soft-recoiling advantages of the intermediate A5 system to standard AR-15 carbines and large-frame platform builds. Designed with an extended internal length, this A5-length 8-position receiver extension increases bolt carrier dwell time, flattens muzzle impulse, and provides micro-adjustable length-of-pull settings for tactical operators and competitive shooters.
Precision CNC-machined from ultra-strong 7075-T6 aluminum and finished in a Mil-Spec Type III hardcoat anodized black coating, the 8P-A5 tube features slick, low-friction internal walls to minimize buffer spring chatter and cycling drag. The 8 discrete adjustment stops give shooters finer stock positioning than traditional 6-position tubes, making it easy to dial in ergonomics for heavy body armor or scope eye relief.
This complete assembly kit includes everything required for a full extension overhaul: the 8-position A5-length buffer tube, a heavy-duty castle nut, and an extended-leg endplate, ensuring drop-in compatibility with standard MIL-SPEC diameter collapsible stocks.
*Armorer Bench Notes & Real-World Staging Guidance:
Fitment Matrix: Fits standard MIL-SPEC AR-15 and AR-10 / SR-25 lower receiver buffer threads (1-3/16"-16 UN). Requires an A5-length buffer and rifle-length buffer spring (sold separately). Fits all standard MIL-SPEC diameter collapsible carbine stocks.
- Verify host lower receiver is completely clear, magazine removed, and chamber visually and physically confirmed empty.
- Thread the included castle nut and endplate onto the 83626 buffer tube with the smooth faces pointing forward toward the receiver.
- Apply a thin layer of aerosol-grade moly grease (MIL-PRF-2105) to receiver threads, then thread the buffer tube into the lower receiver until it captures the buffer retainer pin and spring.
- Align the receiver extension straight, push the endplate forward into the alignment notch, and hand-tighten the castle nut.
- Torque castle nut to 38-40 ft-lbs using a dedicated armorer wrench, then stake the endplate firmly into the castle nut staking notches.
Key Features
- A5 Extended Length System: Utilizes A5 system architecture to smooth out cyclic recoil and delay bolt unlocking.
- 8 Discrete Adjustment Positions: Delivers precise length-of-pull custom fitting for varied body armor or clothing setups.
- 7075-T6 Impact-Forged Aluminum: Premium alloy build provides high resistance against bending, twisting, and receiver boss cracking.
- Mil-Spec Type III Hardcoat Anodized: Deep black protective finish guards against abrasion, perspiration, and environmental wear.
- Complete Assembly Hardware: Includes 8-position tube, castle nut, and endplate for a seamless, out-of-the-box installation.
- Standard MIL-SPEC Outer Diameter: Fully compatible with all standard MIL-SPEC dimension collapsible carbine stocks.
Product Specifications
- Brand: CMC Triggers
- MPN: 83626
- SKU: 83626
- UPC: 810169560686
- Platform Compatibility: AR-15 / AR-10 / SR-25 Lower Receivers
- System Profile: A5 Intermediate Length (8-Position)
- Stock Compatibility: MIL-SPEC Diameter Collapsible Stocks
- Material: 7075-T6 Billet Aluminum
- Finish/Color: Mil-Spec Type III Hardcoat Anodized Black
