SA OBLIVION SR-25 18:1 Precision Steel Gear Set with Improved Timing

OBLIVION SR-25 steel gears with modified timing

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.The OBLIVION series from Specna Arms was designed for players and service technicians who expect high mechanical durability, precise manufacturing and reliable operation from an AEG gear train. The gears are made of durable 40Cr chromium steel, with individual components heat-treated to a hardness corresponding to their load. This version uses a versatile 18:1 gear ratio, providing a good balance between cycle speed, motor load and build reliability. The key feature of OBLIVION is the modified sector gear timing. The cam that controls the tappet plate has been shifted to the area of the second tooth, which improves nozzle movement timing and helps reduce the risk of PME at high RoF. This solution is particularly beneficial for builds with powerful high-speed and brushless motors. Specna Arms also places strong emphasis on manufacturing quality control, making OBLIVION an attractive choice for both regular servicing and building more powerful, faster AEGs.

Key features of Specna Arms OBLIVION SR-25 gears

Technical specifications

• Series: OBLIVION SR-25
• Designed for: AEG V2.5 (SR-25), V4 (PSG-1), L85 and Classic Army SCAR-H (MK17) gearboxes
• Gear ratio: 18:1
• Material: 40Cr steel
• Timing: Modified sector gear timing
• Sector gear hardness: HRC 42–50
• Spur gear hardness: HRC 42–50
• Bevel gear hardness: HRC 42–47
• Gear axle hardness: HRC 55–60
• Weight: 69 g
• Colour: Black

Package contents

• Specna Arms OBLIVION SR-25 18:1 steel gear set

Frequently asked questions from our store

How does the modified timing of OBLIVION gears work?

The cam on the sector gear that controls the tappet plate has been shifted to the area of the second tooth. This changes the timing of the tappet plate and nozzle movement and reduces the risk of PME during very fast gearbox cycling. This is particularly beneficial for builds with very powerful motors.

Can I use these gears in an M4 or AK?

No, the gears are designed specifically for extended V2.5 gearboxes such as those used in SR-25 rifles, as well as the PSG-1 gearbox known as V4, L85 gearboxes and the rare Classic Army MK17 (SCAR-H) version that uses a 19-tooth piston.

Do I need to shim and lubricate new gears?

Yes. After installation, the gears must be properly shimmed, their axial play and mutual meshing checked, and then a suitable lubricant applied. For gears, we recommend PTFE or ceramic grease. Incorrect shimming can increase noise and drivetrain resistance and significantly shorten the service life of both the gears and bearings.