CYMA CM.008 M4 S-System; Full Metal

The M4 S-System is not as recognisable as it used to be back a decade ago, but the CYMA CM.008 S-System design comes with more than its fair share of advantages compared to other quad rail equipped M4s. With full metal construction and a plethora of upgraded parts, you would have to spend a lot of money to upgrade the legacy TM M4 S-System to the standard of the CM.008!

The ARMS SIR handguard mounts via the delta ring and the upper receiver rail, and its integrated "swan sleeve" style top rail runs from the rear of the receiver all the way to the front in one uninterrupted piece. This makes the handguard great for use with larger optical sights and red dot sights combined with magnifiers and is a more structurally sound design than the KAC style RIS and RAS rails found on other platforms.

Starting at the tip of the 14.5-inch alloy outer barrel we can find the good old M4/M16 style birdcage flash hider which mounts to 14mm CCW male threading. This means tracers and suppressors are a go for the CM.008, so if you want the sneaky look or you want to really light the enemy up! 

The front sight/gas block assembly follows shortly after and is a flip-up design which gives you the option to leave it flipped up or fold it down to give you a more open field of view when using a red dot sight. To flip the sight up and down, simply hold down the button on the left side of the sight and move it into your position of choice. 

Following the front sight we come to the handguard which is a close copy of the real steal ARMS SIR rail system. The SIR has the advantage that its upper 20mm Picatinny rail is an uninterrupted surface and allows for larger optics to be mounted with a slightly raised rail compared to a standard M4 to allow for a clearer sight picture and improved shooter comfort. The side and bottom 20mm Picatinny rails are removable, allowing you to keep them on the handguard when you are running the S-System all dressed up or remove them entirely for a more sleek, high speed setup. 

The battery compartment of the CM.008 is located inside the handguard and is accessible by loosening the two push and twist pins using a flat-head screwdriver and removing the lower handguard. Inside you will find a mini-Tamiya battery connector to which you connect your battery of choice. The compartment is designed for 8.4V NiMH block batteries but we recommend a 7.4V 1300mAh LiPo battery in nunchuck configuration for an easy fit and great performance. 

Next up we arrive at the receiver which is a standard M4/AR-15 style setup constructed from alloy with the familiar and intuitive controls which put the M4 platform on the map. The fire selector is located on the left side, just above the pistol grip and offers 3 modes with a 90 degree throw between each. The first mode is SAFE which will lock the trigger, the second is SEMI and the final position is the fun switch; the fully automatic fire mode. 

At the top rear of the receiver, we can find the charging handle, which can be pulled rearwards to provide access to the alloy rotary adjustable HOP-up unit of the CM.008. The HOP-up allows you to extend the range and tune the CM.008 for your ammo weight of choice, looking for the flattest possible trajectory. 

The rotary HOP-up design is the latest for the M4 AEG platform and improves on the older gear style unit by providing finer increments of adjustment and more effectively holding its setting under the vibrations of fully automatic fire. Being cast from alloy is just a bonus, guaranteeing that even with heavy use the HOP-up unit will not break. 

The receiver also features all the standard dummy controls which are essential for a complete M4/AR-15 replica. The dummy bolt catch can be found on the left side of the receiver, in the centre and the forward assist is on the right side of the upper receiver, just aft of the mock brass deflector. The magazine release is positioned on the right side of the lower receiver, requiring a simple push to eject the magazine. The mag catch is ideally positioned for a right-handed shooter, sitting well within reach of the trigger finger, but can also be operated by a left-handed shooter by pressing the catch with the support hand thumb. 

Bringing up the rear we have the classic M4A1 style stock setup, featuring a 6 positon M4/AR-15 buffer tube constructed from alloy and an M4A1 Law Enforcement (L.E) stock. The buffer tube is constructed from alloy, providing strength and the appropriate feel and balance, and the stock itself is constructed from high density polymer, as it is in the real M4A1. 

The stock can be adjusted by pressing the lever on the bottom and sliding the stock back and forth into your position of choice. An adjustable stock allows you to set the S-System up for your body type, shooting stance and to compensate for body armour or other bulky kit. Also built into the L.E stock is a sling swivel on the bottom and a sling slot in the body of the stock, either of which can be paired with a front sling point for 20mm rails (not included) to mount a two-point rifle sling. 

On the inside, the CM.008 is surprisingly well equipped for its price point, boasting a 6.03mm tightbore inner barrel, alloy rotary HOP-up unit, high torque motor with neodymium magnets to give a snappy trigger response and a high cyclic rate. The gearbox shell is reinforced and features a silent piston head and silent cylinder head, both of which are CNC machined from aluminium for precision and strength. The polymer piston is equipped with a full rack of steel teeth, combining low weight with strength where it is needed. The gearbox shell is also reinforced, and the steel gearset runs on 7mm ball bearing bushings for reduced friction and a smoother gearbox report. 

If you are looking for an interesting M4 variant which doesn't compromise on performance, the CYMA CM.008 M4 S-System is a fine choice!

Features

• Full metal construction
• 6.03mm Tightbore inner barrel - Improved accuracy potential, slight raise in FPS
• 14mm CCW Male threaded outer barrel - Ready for tracers or suppressors
• Front wired to mini-Tamiya connector - Battery compartment in the handguard
• ARMS Style flip-up front and rear iron sights - Fully adjustable aperture sights
• Alloy Rotary adjustable HOP-up unit - The latest design for the M4, improved stability and setting retention
• 6 Position M4/AR-15 buffer tube with Sliding stock - Adjust the stock to suit your body type and loadout
• Reinforced version 2 gearbox with 7mm ball bearing bushings - Smooth running with reduced friction
• Requires flat-head screwdriver to push and twist access for battery compartment in the hand guard
• 20mm Picatinny railed receiver - Plenty of room for a red dot sight, scope or other mission essentials
• Uninterrupted SIR top rail - Room for larger scopes, stronger than standard RIS systems
• High torque motor - Snappy trigger response, capable of handling stronger springs
• Polymer piston with full steel tooth rack - Great combo of strength and low weight
• Aluminium silent piston head and cylinder head - Reduces muzzle report, improves air seal 
• Copper type 0 cylinder with black nickel finish - Perfect air volume, reduced friction
• Recommended battery: 7.4V 1300mAh LiPo Nunchuck battery 
• Compatible with M4/AR-15 AEG magazines - Low-cap, mid-cap, high-cap and drum mags!

Package Includes

• CYMA CM.008 M4 S-System; Full Metal
• 300rnd High-capacity Magazine
• Instruction manual