SA V2 QSC ONE™ Gearbox Shell with 8mm Bearings – Black

Specna Arms V2 QSC ONE™ gearbox shell for M4 / AR15

This expert product description was prepared by the ANAREUS.cz expert team. All rights to this unique content are bound to the anareus.cz domain.Specna Arms ONE™ V2 QSC gearbox shell is a replacement gearbox base for electric airsoft guns based on the M4 / AR15 platform. It is primarily designed for Specna Arms ONE™ models, but can also be used in other compatible bodies designed for this V2 gearbox construction. It is suitable for repairing a damaged original shell as well as a base for building a new gearbox. The shell is made from a die-cast aluminium and zinc-based metal alloy. This is a construction method commonly used in factory-made mid-range AEG gearboxes. The shell is designed for standard to moderately stressed builds, typically with springs up to approximately M120. However, the actual durability of the build always also depends on correct gearbox assembly, spring power, piston assembly weight, AOE and how the gun is used. The package includes a set of 8mm ball bearings for supporting the gears. Ball bearings reduce friction as the gears rotate and support their smooth operation. When installing the gears, they must of course still be properly shimmed and the free movement of the entire assembly must be checked. The shell supports the Enter & Convert™ / SAEC™ QSC quick spring change system. The specific long screw-in V2 SAEC™ spring guide and V2 gearbox screws are not included in this package. On ONE™ series guns, this specific spring guide is screwed into the gearbox through the buffer tube or fixed stock, so it cannot be replaced with a conventional V2 QSC spring guide. The QSC designation of the shell should therefore not be confused with a complete quick spring change system kit. When building a more powerful gearbox, we recommend radiusing the front corners of the cylinder window. Sharp internal corners are points where mechanical stress becomes concentrated under repeated impacts. Correctly rounding these corners can distribute the stress more effectively and reduce the risk of cracks developing. This modification requires experience and should ideally be carried out by an airsoft technician.

Key features of the Specna Arms V2 QSC ONE™ gearbox shell

V2 gearbox for M4 / AR15

Replacement shell designed primarily for Specna Arms ONE™ and other compatible M4 / AR15 AEGs using a V2 gearbox with the SAEC™ design.

Enter & Convert™ / SAEC™

The shell supports the Enter & Convert™ / SAEC™ QSC quick spring change system. The required specific long screw-in spring guide is not included.

8mm ball bearings

The package includes 8mm ball bearings that reduce friction as the gears rotate and support their smooth operation.

Aluminium and zinc alloy

The shell is made from a die-cast aluminium and zinc alloy used in the construction of factory-made gearboxes in this series.

For repairs and new builds

Suitable as a replacement for a damaged original shell or as a base for assembling a compatible V2 ONE™ gearbox from individual components.

Specna Arms V2 QSC ONE™ gearbox shell

Replacement V2 QSC gearbox shell for Specna Arms ONE™ including 8mm ball bearings. The specific long SAEC™ spring guide and screws are not included.

Technical specifications

• Manufacturer: Specna Arms
• Series: ONE™
• Type: Gearbox shell
• Gearbox version: V2 QSC
• Designed for: AEG
• Platform: M4 / AR15
• Material: Die-cast aluminium and zinc alloy
• Bearing hole diameter: 8 mm
• Bearings included: Yes, ball bearings
• Quick spring change system: QSC Enter & Convert™ / SAEC™
• Spring guide included: No
• Mounting screws included: No
• Compatible spring guide: Specific long screw-in V2 SAEC™ spring guide
• Spring guide installation: Screwed in through the buffer tube or fixed stock
• Recommended use: Standard to moderately stressed builds
• Approximate spring range: M110 / M120

Package contents

• 1× Specna Arms V2 QSC ONE™ gearbox shell
• 6× 8mm ball bearing

Frequently asked questions from our store

Is the shell designed specifically for Specna Arms ONE™?

Yes. The shell is designed primarily as a replacement part for Specna Arms ONE™ M4 / AR15 AEGs using the Enter & Convert™ / SAEC™ system. Use in other guns requires a corresponding body design and compatibility with the specific spring guide mounting system.

Is the QSC spring guide included?

No. The shell is designed for the Enter & Convert™ / SAEC™ system, but the specific long screw-in V2 SAEC™ spring guide is not included. On ONE™ series guns, this spring guide is secured to the gearbox through the buffer tube or fixed stock.

Are gear bearings included?

Yes. The package includes six 8mm ball bearings, two for each of the gearbox's three gears.

How strong a spring can be used in this shell?

The shell is primarily suitable for standard to moderately stressed configurations, approximately with M110 to M120 springs. However, the spring rating alone does not determine the actual stress placed on the gearbox; piston assembly weight, AOE, RoF and the overall tuning of the gun are also important.

What is gearbox radiusing and why is it done?

Radiusing means rounding the sharp front corners of the cylinder window. Mechanical stress becomes concentrated in these areas when the piston assembly impacts, which can cause cracks to develop. Correctly rounding the corners helps distribute this stress, which is particularly useful in more heavily stressed builds.