Wolverine Inferno 2 / Reaper 2 + Begadi Neptune Pro alignment kit for M4 AEG (v2.1)

Version 2.1 of the hop-up alignment system, specifically designed for M4 AEG HPA replicas using:

• Wolverine Inferno 2 or Reaper 2 engines (compact HPA engines with high airflow and precise configuration).
• Begadi Neptune Pro chamber (high-performance hop-up chamber with micrometric adjustment system and lips control optimized for HPA).

This system ensures absolute centering of the nozzle relative to the Neptune Pro chamber, eliminating BB feeding variations and maximizing pressure efficiency in high-performance setups. The kit geometry is adapted to the compact design of both the Inferno 2 and the Reaper 2.

Compatibility

Component	Compatibility
HPA Engine	Wolverine Inferno 2 / Reaper 2
Hop-up Chamber	Begadi Neptune Pro
Base Replica	M4 AEG
Gearbox	V2 / ICS SPLIT

What the kit includes

• Rear clip for mounting via rear pin or fixed stock.
• Base with housing for M3 inserts (optional brass).
• Side clip for guiding the HPA tube/line specifically designed for Wolverine engines.
• Front locking top cap adapted to the geometry of the Neptune Pro chamber.
• Rear plate with mounting point for an M5 screw (additional reinforcement).

Installation and adjustment

1. Printing and preparation

   • Print the parts with 65–80% infill.
   • Perform light sanding on internal and contact areas for a clean fit.
   • Apply dry lubricant or wax on sliding surfaces if you plan frequent maintenance.

2. Installation in the replica

   • Insert the base into the lower and secure the M3 inserts in their housings.
   • Install the rear clip aligned with the rear pin or stock anchor point.
   • Install the Begadi Neptune Pro chamber with the inner barrel; the top cap locks the assembly while maintaining the micrometric position of the chamber.
   • Route the Inferno 2 / Reaper 2 HPA line through the side clip specifically designed to prevent bends.

3. Final fixation

   • Use an M5 screw with washer on the rear plate for maximum rigidity.
   • Verify that the Wolverine nozzle enters perfectly centered into the Neptune Pro chamber without lateral play.
   • Perform dry feeding tests and adjust the Neptune Pro micrometric hop-up according to your BBs and bucking.

Required components (not included)

• 4× M3 × 4.2 mm inserts
• 4× M3 × 8 SHCS screws

Lower receiver recommendations

It is recommended to use the ICS metal lower receiver for maximum rigidity.
If you prefer to print the lower part, the following Gearbox V2 Lower “Universal Lower Part” models are compatible:

• Version 3
• Version 4.2
• Version 4.3 MTW

You can find them HERE.

3D printing parameters

• Approximate print time: ~1 h 30 min
• Recommended material: PLA+
• Layer height: 0.10 mm – 0.15 mm

Manuals

Installation and adjustment manuals are available in the Manuals section of the website or on the project’s Discord server.

Related products and articles

Similar product designs:

• Wolverine Inferno 2 / Reaper 2 + BEGADI Neptune PRO alignment kit for SCAR-L (v2.1)
• wolverine inferno2 reaper2 begadi neptune pro
• Wolverine Reaper 2 / Inferno 2 + Silent Industries alignment kit for M4 AEG (v2.1)

Technical articles for this topic:

• MAXX Model Hop-Up: Differences Between Models, Versions, and Compatibility with HPA Kits
• Difference between kit versions