CTM M4XIMUS HPA Frame Conversion Kit for Tokyo Marui Hi-Capa Pistols

High-performance HPA conversion for Hi-Capa platforms. The CTM M4XIMUS HPA Frame Kit brings rifle-grade capacity and durability to your gas blowback pistol setup. Designed specifically for Tokyo Marui Hi-Capa 5.1 and 4.3 models, this kit enables the use of standard AEG M4 magazines and an external HPA setup.

Streamlined BB path and custom mag housing for seamless performance. The heart of this system is a specially designed magazine housing that interfaces with your own feed lips and nozzle seal to provide reliable BB delivery under high pressure. The M4 magazine adapter includes a BB-locking mechanism to prevent spills during reloads, and a precision-machined CNC mag release ensures fast, confident mag swaps.

Built for competitive play and durability. The frame is constructed from a high-strength nylon polymer infused with 45% fiberglass for rigidity and resilience. The Polka dot style grip panels offer a secure, non-slip texture, and the open magwell window gives visual confirmation of BB feed in real time. Every detail of this kit was engineered to maximize your edge on the field without sacrificing compatibility or ease of use.

Features

• Drop-in HPA conversion kit for TM Spec Hi-Capa 5.1 and 4.3 pistols
• Works with all Hi Capa upper receivers and mag wells; not compatible with non-standard triggers
• Compatible with AEG M4 magazines from brands like PTS, G&G, Guarder, and Poseidon
• No internal FCU or HPA engine required — runs off standard tank, regulator, and line
• Frame and mag housing made from high-strength 45% glass-reinforced nylon
• Polka dot style grip panels for confident handling and aesthetics
• Open BB feed window integrated into trigger guard
• BB-locking mechanism on M4 adapter prevents BB loss during mag changes
• Precision CNC-machined M4 mag release button
• Uses your existing Hi-Capa trigger and mag internals (feed lips and seal required)

Specifications

Overall Length: 8.0 in (approx.)
Weight: 200 g
Material: 45% fiberglass-reinforced nylon, CNC 6061 aluminum, stainless steel
Gas Type: HPA (via external tank, regulator, and line)
Blowback: Yes
Firing Modes: Semi-auto
Muzzle Velocity: Dependent on HPA regulator setup
Magazine Capacity: Determined by M4 AEG magazine used
Hop-Up: Adjustable (retains original Hi-Capa hop-up unit)
Threaded Barrel: Based on upper used (not included)
 Pistol Compatibility: Tokyo Marui Hi-Capa 5.1 & 4.3 and other compatible gas blowback Hi-Capa models
Compatible Magazines: Standard AEG M4 magazines (e.g., PTS, G&G, Guarder)
Color: Black (BK), Tan (TAN), Pink (PNK)
Package Includes: HPA frame kit, proprietary mag housing (requires user-supplied Hi-Capa feed lips and nozzle seal)