Airsoft M4 AEG Billet CNC 8mm Ver.2 Split Gearbox Shell

Retro Arms CZ CNC Billet Airsoft Gearbox Shell

Engineered for precision shooters seeking unmatched durability and upgrade flexibility, this CNC-machined 7075-T651 aluminum gearbox shell redefines reliability for M4/M16-style AEGs. The split upper/lower design eliminates full disassembly during internal upgrades – simply remove the top half via receiver pin for effortless piston assembly or spring tension adjustments.

Key performance advantages:
– Military-Grade Construction: Solid billet machining with stress-point reinforcements withstands M160 spring forces (tested to 50k+ cycles) without deformation
– Speed-Optimized Mechanics: Patented ball-bearing spring guide enables 90-second spring swaps – no tools or gearbox teardown required
– Impact Distribution System: Pre-radiused cylinder windows + dual-layer wire channels reduce barrel wobble by 40% under rapid fire
– Corrosion-Proof Finish: Hard-anodized surface resists field wear while maintaining lightweight build (142g vs cast alternatives)

Compatible with Tokyo Marui, G&P, Matrix and most M4-series airsoft rifles (minor shim adjustments may apply for non-TM brands). The stainless steel mounting bolts provide vibration-dampening security that generic polymer shells can’t match.

Ideal for tournament players needing rapid response upgrades or field technicians maintaining rental fleets – this shell combines pro-grade durability with DIY-friendly servicing that keeps your AEG running at peak performance season after season.