Specna Arms CNC Aluminum Cylinder Type 2

Specna Arms CNC Aluminium Cylinder Type 2 is a CNC-machined aluminium cylinder for AEG gearboxes that optimises the air volume for replicas with a medium-length inner barrel. The Type 2 port enables more efficient air compression, resulting in more consistent energy transfer and reduced FPS fluctuations when the compression set is correctly assembled.

When it comes to gearbox upgrades, people often immediately think of a stronger spring or a precision barrel, whilst it is actually the ratio between cylinder capacity and barrel length that has a major influence on the final performance. A Type 2 cylinder has been developed for replicas with an inner barrel of approximately 300 to 400 mm, making it a logical choice for many M4, HK416, SCAR and similar AEG platforms.

Why a Type 2 cylinder makes all the difference

A Type 2 cylinder has a partial port, meaning that less air is compressed than in a fully closed Type 0 cylinder. Whilst this may appear to be a limitation on paper, it is actually designed to better match the air volume to medium-length barrels. If a cylinder supplies too much air for the barrel being used, over-volumisation occurs. This can lead to unnecessary pressure build-up, extra strain on the compression set and less consistent shots.

With a correctly chosen Type 2 cylinder, the available air is utilised more efficiently. You’ll notice, particularly during fast semi-automatic bursts or longer days of play, that the replica performs more consistently because the compression is virtually identical in every cycle.

A common mistake is to combine a Type 0 cylinder with a relatively short or medium-length precision barrel. This results in some of the available air volume being lost without delivering any additional performance.

CNC-machined aluminium for a precision compression set

The Specna Arms CNC Aluminium Cylinder Type 2 is fully CNC-machined from aluminium. This ensures precise tolerances, which is important for a good fit between the cylinder, cylinder head and piston head.

In addition, the smooth finish on the inside ensures that the piston head moves smoothly through the cylinder. Less internal resistance means a more stable compression stroke and a more even load on the O-ring during prolonged use.

During overhauls, it is often apparent that cheap cylinders have slight burrs or an uneven inner wall. This accelerates wear on the piston head O-ring and, over time, can adversely affect the air seal.

A better balance within the complete compression set

The cylinder never functions as a separate component. Optimum performance is achieved when all compression components are matched to one another.

Consider combining this with:

• a CNC-machined cylinder head for a precise seal
• a double-sealed piston head for maximum airtightness
• a high-quality nozzle of the correct length
• a precision inner barrel measuring approximately 300 to 400 mm

It is precisely this combination that ensures the available air is utilised almost entirely, thereby accelerating the BB at a constant pressure.

When do you notice the difference?

A correctly tuned Type 2 cylinder does not automatically result in a higher FPS. The greatest benefit actually lies in the consistency of each shot.

You can tell this, amongst other things, from:

• a smaller variation between consecutive FPS measurements
• a more consistent hop-up performance, as the air pressure is more even
• more predictable ball flight at medium range
• less variety during longer match days or intensive training sessions

For players who want to fine-tune their replica, a stable compression setting is often more valuable than a higher peak FPS.

Practical applications

This Type 2 cylinder has been developed for replicas with a medium-length inner barrel of approximately 300 to 400 mm. This makes it ideal for, amongst other things:

• M4 AEGs with standard barrel length
• The HK416 platform
• SCAR-L and similar models
• various Version 2 and Version 3 gearboxes during maintenance or complete overhauls

In both CQB and outdoor set-ups, a well-calibrated air volume continues to contribute to a predictable shot pattern.

A common mistake with gearbox upgrades

Fitting a precision barrel without reassessing the cylinder capacity is one of the most common mistakes made during upgrades.

If the barrel becomes longer or shorter than the original configuration, the existing cylinder may not be able to match the required air volume as effectively. As a result, the potential of the new barrel is not fully utilised.

You should therefore always check that the cylinder, nozzle, cylinder head and barrel function together as a single compression system.

Key features

• CNC-machined aluminium ensures a precise fit within the gearbox and helps maintain a consistent compression stroke.
• Type 2 air volume is designed for inner barrels measuring approximately 300 to 400 mm, ensuring that the volume ratio remains more efficient.
• A smooth, polished interior reduces internal resistance and helps the piston head to move smoothly.
• Suitable for overhauls and performance upgrades in which the entire compression set is rebuilt or optimised.

Who is this cylinder suitable for?

This cylinder is a logical choice for players who wish to optimise their AEG’s performance and correctly adjust the compression set to suit a medium-length inner barrel. It also provides a reliable basis for a new airseal when carrying out a full gearbox overhaul.

If you are using a very long inner barrel of around 450 mm or longer, a Type 0 cylinder is generally a better choice due to its greater air volume. For shorter barrel configurations, however, a Type 3 or Type 4 cylinder may actually be more efficient.

Frequently Asked Questions

What inner barrel length is a Type 2 cylinder designed for?
Generally speaking, for AEGs with an inner barrel of approximately 300 to 400 mm. This provides a good balance between air volume and barrel length.

Does a Type 2 cylinder automatically produce a higher FPS?
No. The main aim is to achieve a more consistent energy transfer and more efficient compression. The benefits usually lie in more stable FPS readings and a more predictable shot pattern.

Can I combine this cylinder with a precision barrel?
Yes. It is precisely when combined with a precision barrel, a suitable nozzle and a high-quality cylinder head that the benefits of a well-tuned compression set really come into their own.

Does this cylinder fit both Version 2 and Version 3 gearboxes?
Yes, provided the gearbox uses a standard AEG cylinder in accordance with the usual specifications.

When should I replace my cylinder?
If there is visible wear and tear, damage to the inner wall, a complete gearbox overhaul, or if you change the stroke length and want to re-tune the compression set.

Would you like to put together an AEG compression set that’s perfectly suited to the length of your inner barrel? If so, the Specna Arms CNC Aluminium Cylinder Type 2 is a well-designed foundation for a reliable and consistent gearbox upgrade.