Bobbly's Precision TDC Hop-Up Chamber for VFC AR15 / M4 / APFG MCX GBBR

⚠️ Important: This hop-up chamber is intended for experienced GBB users and tuning enthusiasts. Depending on platform tolerances and build configuration, minor fitting work may be required. Bobbly Precision TDC Hop-Up Chamber for VFC AR15 / M4 / APFG MCX GBBR The Bobbly Precision TDC Hop-Up Chamber is a modern TDC-style upgrade solution designed for the VFC AR15 / M4 GBBR platform as well as the APFG MCX series. Built around a clean and practical adjustment concept, this chamber provides more consistent pressure application and improved tuning precision compared to standard factory-style hop-up systems. The chamber follows the familiar dimensions and compatibility standard widely adopted within the modern VFC GBB ecosystem while introducing several refinements aimed at practical usability and broader compatibility. TDC Adjustment System The chamber uses a Top Dead Center (TDC) adjustment system, allowing more direct and consistent hop pressure application onto the bucking. Adjustment is performed similarly to the newer VFC and GHK V3-style systems, using an M2 Allen key through the fake shell ejection port. Existing factory-style VFC and GHK adjustment tools can also be used, and Bobbly Precision adjustment tools will be available as a dedicated companion solution. Key Features TDC-style hop-up adjustment system Compatible with VFC AR15 / M4 GBBR and APFG MCX platforms Adjustment via M2 Allen key from behind, or GHK or VFC hop up adjustment tool from the fake ejection port is recommended. The custom-designed adjustment grub screw provides exceptionally precise hop-up tuning with clear tactile feedback. Additionally, two side-mounted locking grub screws with tensioned roller balls create a unique dual-side anti-movement system, helping the hop-up setting remain stable and consistent even under the recoil impulse of demanding GBBR platforms. Improved C-clip design with support for VSR inner barrels Designed as a practical and affordable performance upgrade for the VFC GBB ecosystem Included CNC POM Shim Pieces To improve compatibility across different models, the package includes two CNC-machined plastic shim spacers: 3mm blue shim – for VFC AR15 and M4 GBB models 2mm red shim – for APFG MCX platforms, must be used together with the Bobbly Precision enhanced chamber base When used on APFG MCX GBB, must be used together with our chamber base: View Enhanced APFG MCX Chamber Base Included TDC Precision Bucking As an included bonus, the package also contains one 70 degree TDC Precision Bucking. Before installation, the side wing of the bucking needs to be trimmed for proper fitment within the chamber system. Additional buckings: View TDC Hop-Up Rubber Compatibility Notes Compatible with VFC AR15 / M4 GBBR platforms, not HK416A5 Compatible with APFG MCX series only together with Bobbly 4UAD Chamber Base Supports VSR inner barrels due to revised C-clip geometry GHK compatibility has been tested successfully, although minor sanding or fitting work may be required depending on the build Why Upgrade? Compared with standard factory hop-up chambers, the Bobbly Precision TDC chamber offers a more refined adjustment system, improved consistency, and broader tuning flexibility. It is especially attractive for users looking for an affordable and performance-oriented TDC solution within the VFC / GBB ecosystem while maintaining compatibility with commonly used tuning components and tools. Technical Specifications Platform Compatibility VFC AR15 / M4 GBBR, APFG MCX Adjustment Type TDC (Top Dead Center) Adjustment Tool M2 Allen key Adjustment Access Through fake shell ejection port Inner Barrel Compatibility VSR compatible Included Bucking 70° TDC Precision Bucking Included Shims 2mm + 3mm CNC spacers Package Disclaimer This product is intended for airsoft use only. Due to varying tolerances between different manufacturers and production batches, minor fitting or sanding work may occasionally be required. This is normal for advanced GBB tuning parts and does not constitute a defect.