Custom Block II – Hop Control

We don't optimise a single component. We optimise the entire system.

Custom Block II – Hop Control is the second level of the PRIMOREGGIMENTO.COM upgrade programme. It includes all Custom Block I – Precision work and adds specific improvements to the mechanical stability and control of the hop-up assembly.

Starting from €169.00.

The objective is to reduce mechanical play and misalignment that can affect shot repeatability, creating a more stable and adjustable system even during regular use.

Features and technical specifications

• Workshop: PRIMOREGGIMENTO.COM
• Service: hop-up optimisation and structural alignment
• All Custom Block I – Precision work, including a precision inner barrel, high-performance bucking, cleaning, adjustment and spring replacement when necessary
• Installation of a high-quality CNC-machined hop-up chamber
• Installation of a dedicated hop-up nub
• Inspection and optimisation of alignment between the gearbox, hop-up chamber, inner barrel, outer barrel and replica body
• Buffer tube positioning and structural component checks where applicable
• Stabilisation of components prone to misalignment, using threadlocker when necessary
• Chronograph checks and final functional testing
• Components: normally Retro Arms, Maple Leaf or equivalent products of comparable quality, selected for the platform

Accuracy depends on stability

The hop-up assembly connects the feeding system to the inner barrel. Incorrect component fit can affect nozzle positioning, feeding consistency and how the hop-up effect is applied.

A high-quality CNC-machined chamber can provide more precise tolerances and greater stability, but it must be compatible and properly integrated into the replica. This is why the service also addresses the components supporting and aligning the assembly rather than stopping at chamber replacement.

Targeted improvements

• Greater accuracy and shot repeatability, including at longer distances
• More precise and progressive hop-up adjustment
• More consistent BB feeding
• Reduced dispersion caused by mechanical play and misalignment
• An optimised foundation for subsequent Custom Block levels

Final performance depends on the replica's initial condition and manufacturing tolerances.

Frequently asked questions

Does Block II fully include Block I?

Yes. The second level includes all first-level work, adding the CNC hop-up chamber, dedicated nub and thorough structural alignment checks.

Why install a dedicated hop-up nub?

The nub determines how adjustment pressure is transferred to the bucking and therefore to the BB. It is selected to suit the installed system and provide more controlled, uniform hop-up contact.

Is a CNC hop-up chamber compatible with every replica?

No. Dimensions and component fit vary between platforms and manufacturers. Compatibility is checked before installation. Even a high-quality chamber may perform poorly if it does not suit the replica.

The Custom Block philosophy

We have been studying and upgrading airsoft replicas since 1997. In 2004, this experience became part of the everyday work of PRIMOREGGIMENTO.COM.

The Custom Block method combines selected components, careful tolerance checks and individual tuning. The value of the service lies not only in the quality of the parts, but in the expertise required to make them work correctly together.