CYMA CGS 14.5" M4A1 RAS SOPMOD GBBR

CYMA
Code: FB4112
582.99
  • Full metal construction
  • 6.04mm Tightbore inner barrel
  • Tokyo Marui ZET system based internals

If you like an aggressive military-style AR, the CYMA CGS 14.5" M4A1 RAS SOPMOD GBBR should suit your needs. This full metal gas blowback rifle is based on the real steel M4A1 in SOPMOD Block 1 configuration, equipped with a CNC aluminium 20mm Picatinny quad rail patterned after the real steel KAC RAS. This is the perfect platform for a US Army impression!

Internally, this beast is based on the Tokyo Marui ZET system, giving you the best current option for GBBR internals with the widest aftermarket for upgrade parts. You won't need many upgrades though; with almost entirely steel trigger parts, a steel bolt carrier, a steel bolt catch and a 6.04mm tightbore inner barrel, the CGS M4A1 is ready to rock straight out of the box!

Full description

Description

Whether you are getting into Milsim and need a realistic M4A1 replica or you're ready to take your first punt on a GBBR but aren't sure where your build will take you, the CYMA CGS 14.5" M4A1 RAS SOPMOD GBBR is ideal. Based on the much-lauded Tokyo Marui ZET system on the inside but absolutely brimming with steel upgrade parts, the CGS M4A1 is fantastic value and comes in a flexible configuration which can be chopped and changed to suit your mood, with the appropriate tools and skills of course!

The real steel M4A1 serves as the US Army's standard issue service rifle and has served throughout innumerable conflicts in the hands of everyone from the US Army Rangers to Navy SEALs and Delta. The CGS M4A1 replicates the M4A1 following its SOPMOD Block 1 upgrade, with a pre-installed KAC-style 20mm Picatinny quad-railed handguard, flip-up rear sight and packaged with a KAC-style vertical foregrip and rail covers. All you need to complete the SOPMOD Block 1 looks is an ACOG or Aimpoint-style optical sight!

Starting at the front, we can see a steel birdcage flash hider mounted to the 14mm CCW male threading at the tip of the 14.5-inch alloy outer barrel. This means the M4A1 is ready to be kitted out with a tracer unit or suppressor, or an alternative muzzle device for a more customised look. If you are going for the full SOPMOD build look, add this suppressor if you are going silent!

The outer barrel profile between the flash hider and front sight matches the real steel M4A1 perfectly, including its 5.56 NATO, 1/7 twist and proof markings. It's always nice to see this extra level of detail in an Airsoft RIF, evidence that CYMA values realism. The barrel profile also includes the M203 cutout around halfway between the tip and front sight, meaning you can add a full-length M203 Grenade launcher and mount it the same way the US Army does.

Next up, we come to the M4A1 style triangular front sight post, which is constructed from steel and houses the front sight and mock bayonet lug. The bayonet lug is functional in the 14.5-inch barrel length, meaning you can add a Ghost M9 Rubber Dummy Bayonet for knife kills and classic bayonet charges. The front sight itself is adjustable for elevation using an M4/AR-15 front sight adjustment tool, and for less precise work up close it can be used as an index point for rapid aiming when there is no time to align the sights.

Mounted to the bottom of the front sight assembly we have our first sling point, which is a standard steel footman loop compatible with a wide variety of sling types. This can be paired with the rear sling point on the stock to fit a two-point rifle sling to take the burden off your arms or allow for easy transitions to a sidearm. The perk of a relatively old-school design is that all the sling points are built in, meaning no extra adapters are needed!

Following the front sight, we come to the RAS handguard assembly which is constructed from a combination of alloy, steel and CNC aluminium. The handguards themselves are a great replica of the real steel KAC RAS, a 2-piece 20mm Picatinny quad rail handguard with ribbed rail covers pre-installed to enhance wet weather handling. The handguards are held in place using a steel handguard cap at the front, and an alloy delta ring at the rear. Being made in two parts, the RAS handguard allows you to remove the lower handguard and mount an M203 grenade launcher to the barrel for some extra firepower and a more intimidating form factor.

The modularity of the M4 platform is easily its best feature, and it is no surprise that it gained the nickname "Barbie for men" following its "SOPMOD Block 1" upgrade. This modularity also extends to exchanging external parts, and with an M4/AR-15 armourers' wrench, you can change the entire front set of the M4A1 RAS and make it look like practically any M4/AR-15 variant out there. Even if you don't have an armourers' wrench, the delta ring front end is compatible with any 7-inch drop-in rail system or handguard set for delta rings, so if you want to change up the looks of your M4A1 you'll be happy to learn that it can be done without a single tool!

Moving rearward we reach the receiver, which is a familiar M4/AR-15 layout, matching the real M4A1 perfectly. The receiver is constructed from alloy with a matt black finish and is equipped with a steel dust cover, bolt catch and body pins. The fire selector is located on the left side of the AEG and sits directly above the pistol grip to provide fast and easy access for right-handed shooters. With a 90-degree throw between modes, the fire selector is quick to operate but not too easy to accidentally knock it and end up in the wrong fire mode. Each fire mode is indicated with standard M4A1 markings reading "SAFE - SEMI - AUTO" in nice, crisp engravings. Like many GBBRs, the CGS M4A1 cannot be put into the "SAFE" mode without first being cocked, just like a real M4!

The bolt catch is right where we would expect; on the left side of the receiver, smack bang in the centre. On a GBBR, the bolt catch works exactly like the real thing, allowing you to quickly return the bolt carrier to battery after a reload and avoid using the charging handle. As with most of the hard-wearing parts on the CGS M4A1 RAS, the bolt catch is constructed from steel, ensuring reliable bolt locking in the long term.

The magazine release is on the right side of the magazine well and is ideally positioned to be pressed with the trigger finger from a firing grip for right-handed users. Left-handed users can use their support hand thumb to press the release, and this can be done quite fast with a little practice. The surface of the mag release is textured to provide the necessary gripping qualities, and is protected from accidental presses by the "magwell fence", a raised protrusion in the receiver which stops the mag release from catching on your gear as you move.

The HOP-up unit of the CGS M4A1 RAS is located inside the upper receiver, following the Tokyo Marui ZET system format. Taking the form of a small screw inside the front of the upper receiver, the HOP-up adjustment dial is accessible through the magazine well using a small flathead screwdriver. This is slightly different than the TM ZET System, using a screw instead of the gear inside the TM. The screw system actually makes the HOP-up easier to adjust and avoids the need to remove the charging handle and bolt carrier to access the adjuster easily. The easiest way we found to set the HOP-up is by locking the bolt to the rear and adjusting through the magwell. The HOP-up allows you to tune the M4A1 RAS for different ammo weights and extend your range, looking for the flattest possible trajectory.

The pistol grip is the legendary "A2" type, first seen on the M16A2 and common on military builds. The grip boasts textured panels on each side for improved traction and a finger ridge to help support and control the front end of the Shorty when held in the "high ready" position. The pistol grip is compatible with real steel and TM ZET system aftermarket replacements should you have a preferred grip for your build.

Following the receiver, we reach the AR buffer tube, which is a common part found on the vast majority of M4/AR-15 AEGs and GBBRs. This buffer tube is constructed from alloy and provides 6 positions of adjustment for the pre-installed L.E style stock, enough to suit any body type or loadout. The buffer tube system allows you to swap your stock out for any aftermarket M4/AR-15 stock simply and quickly, so if you get tired of the looks of the M4A1 in the future, swapping out the stock can style it up! A second sling point is positioned at the toe of the stock, allowing you to mount a two-point sling and take the burden off your arms during downtime or long-duration skirmishes.

On the inside, the CGS M4A1 RAS is based on the Tokyo Marui ZET System used in its MWS M4A1. This is already a flex, as the TM system is known to be far superior to other GBBR systems and has the widest aftermarket for upgrades. Speaking of upgrades, CYMA/CGS has sorted many of the known weak points in the TM design by using steel trigger parts, giving you a longer-lasting GBBR platform and saving you a wad of cash when it comes to upgrading down the line.

To provide super strong recoil and an immersive firing experience, CGS added a steel bolt carrier to the ZET System formula, providing heightened immersion thanks to its extra mass. This also means you will need to use a stronger gas than you might in a Tokyo Marui to get the same rapid-fire performance. Also present in the CGS build is a 6.04mm tightbore, giving an edge in accuracy potential and gas efficiency, letting this short rifle do some good work at long range.

Whether you are working on your US Army impression or want a classic M4A1 to add to the collection, you can't go wrong with the CYMA CGS 14.5" M4A1 RAS SOPMOD GBBR. Based on what is rapidly becoming known as the best GBBR internal system but packed with steel parts, this platform represents previously unheard-of value for money!

Features

  • Full metal construction
  • Gas Blowback Rifle - Heavy recoil, realistic handling, low-cap mags - A rifle for the pros!
  • 14mm CCW male threaded outer barrel - Ready for a suppressor or tracer
  • Steel Birdcage flash hider - Ideal for military-style builds
  • High density polymer M4A1 ribbed handguards - Comfortable and lightweight
  • Delta ring handguard attachment method - Compatible with aftermarket handguards for delta rings
  • Compatible with Ghost M9 Dummy Bayonet - Ask the marshalls before using one though!
  • 20mm Picatinny railed receiver - Ready for a red dot sight or scope
  • 6-Position M4/AR-15 buffer tube - Adjust the stock to fit your body type and loadout
  • Adjustable L.E stock - The classic Colt style Law Enforcement stock
  • Low profile "milspec" charging handle - Reduced snag points, steel latch for rigidity
  • "A2" Finger ridged pistol grip - Ideal for military-style builds, compatible with aftermarket real steel AR grips
  • QD Sling plate - Add a single-point sling using a QD sling swivel
  • 5.56mm Marked polymer dust cover - Modern dust cover, very well suited to modern builds
  • Gear adjustable HOP-up - Inside the upper receiver, accessible through the magwell, requires a flathead screwdriver
  • Full steel trigger group - Save you precious money on upgrades, these will probably last forever
  • Steel bolt catch - Another high-wear part made from steel!
  • Tokyo Marui ZET system-based internals - Compatible with TM ZET system aftermarket upgrades
  • Is this your first GBBR? If so, see the "Special Instructions" section below or our GBBR Guide

Package Includes

  • CYMA CGS 10.5" M4A1 CQB GBBR
  • 30rnd Green Gas Magazine
  • User manual (QR Code)
  • Cleaning rod
  • Speedloader

Special Instructions

This is a Gas Blowback Rifle. GBBRs require maintenance and careful handling and we do not recommend them for new skirmishers. Things to watch out for if this is your first GBBR:

  • The rifle cannot be put into "Safe" mode without first being cocked. Generally, the best way to store a GBBR is with the magazine removed, the rifle uncocked and the fire selector set to "semi". Do not force the selector into "Safe" when the rifle isn't cocked; this will damage the trigger group parts.
  • The HOP-up adjuster for this TM ZET system GBBR is inside the upper receiver and is accessible through the magazine well using a flathead screwdriver when the bolt is locked open.
  • GBBRs need to be cocked before the first shot, just like a GBB pistol. It is important that you do not double load a GBBR as this can break the nozzle. We recommend clearing the chamber of BBs with a cleaning rod in the event that you finish firing mid-magazine and the bolt does not lock back and show an empty chamber.
  • GBBRs generally use higher pressure gas than GBB pistols due to the extra weight of the bolt. We recommend Green Gas (NUPROL 2.0, VORSK V6, ASG Ultraair) for general use and Red Gas (NUPROL 3.0, VORSK V8) for cold weather use.
  • The faster you shoot a GBBR, the less accurate it will be. This is due to pressure variance as the gas reservoir cools down. Full auto is basically for fun, and these rifles run far better when used in semi-auto mode.
  • Like a GBB pistol, GBBR magazines require maintenance. We recommend leaving a small amount of gas inside the magazine when stored, and not storing the magazines in a cold or damp environment. Magazine seals and valves will need lubrication and to be kept clear of dust and debris.

Specification

General

Weapon Construction External
Weapon Type
Assault Rifle
Over 18 Only Icon
Over 18
Yes
Icon UKARA - United Kingdom Airsoft Retailer Association
Defence / UKARA Required
Yes, No,
FPS Icon
FPS (Feet Per Second), using 0.20g BB
Approx. 350fps ± 10%, using 0.20g BB
Site Legal Icon
Site Legal, using 0.20g BB
Yes
Screwdriver Icon
Pre-Built
Yes
Package
Included Items
  • Magazine
  • Cleaning Rod
  • Speed Loader
  • PVC Patch
Skill Level Icon
User Skill Level
Regular Player, Experienced Player,
Patrol Base - Warning Icon
Warnings
Lubrication is required
This GBBR cannot be put into the SAFE mode without first cocking the rifle. Do not force the selector into safe whilst the weapon is not cocked.

Weight and Dimension

Weight KG Icon
Weight (KG)
Approx. 2.52kg
Weapon Length Collapsed
Length (Collapsed)
77cm
Weapon Length Extended
Length (Extended)
85cm

Construction

Colour Wheel Greyscale
Primary Colour
Black
Construction Icon
Construction
Steel flash hider, sling points, handguard cap, dust cover, pins, bolt catch, castle nut & charging handle latch. Alloy outer barrel, receiver & buffer tube. Aluminium handguard. Polymer stock/grip
Weapon Construction External
External Construction
Polymer
Alloy
Aluminium
Steel
Gearbox Icon
Internal Construction
Polymer
Alloy
Aluminium
Steel

Weapon Specific

Power Source Icon
Powered By
Green Gas
Blowback Icon
Blowback
Gas Blowback
Weapon Platform
AR, M4 / AR-15 / M16, Assault Rifle,
Magazine Style Icon
Magazine Style
Long Gun Magazine, Assault Rifle, M4 / AR Platform, TM ZET System M4/Type 96 GBBR Magazine,
Fire Select Icon
Fire Selector
PatrolBase | Fire Select Safe
Safe
Patrol Base | Fire Select - Semi Automatic
Semi Automatic
Patrol Base | Full Automatic
Full Automatic
Weapon Safety Features Icon
Safety Features
Trigger Lock
Shooter Configuration Icon
Shooter Configuration
Right Handed
Weapon Configuration Icon
Weapon Configuration
Standard
Weapon Scale Icon
Weapon Scale
1:1
Suggested BB Weight
0.25g

Hop-Up

Hop-Up Unit Icon
Hop-Up Unit
Yes
Hop-Up Unit Adjuster Icon
Hop-Up Adjuster
Gear
Hop-Up Unit Location Icon
Hop-Up Location
Inside the top of the upper receiver, accessible with the bolt locked open or when the rifle is field stripped.

Furniture

Weapon Furniture Icon
Furniture
  • Railed Handguard
  • AR Buffer Tube
  • Railed Receiver
  • Finger Ridged Pistol Grip
  • Sliding Stock
  • Bird Cage Flash Hider
  • sling points front and rear
  • Flip up rear Iron sight
  • AR Triangle front sight with sling loop
  • Bayonet lug
  • Aperture iron sights
  • Outer barrel with M203 cut
Rail System Icon
Rail System
20mm RIS / RAS , 20mm Railed Receiver,
Icon Stock Positions
Stock Setting
Sliding , Multi-Position ,
Weapon Length Extended
Stock Positions
6 Position
Sight Type Icon
Sight Type
Iron Sights , Aperture Iron Sight,
Sling Plate Icon
Sling Options
Stock , Loop , Gas Block,

Barrel

Outer Barrel Length (in)
14.5''
Icon Thread Type
Outer Barrel Thread Type
Male
Icon Thread Direction
Outer Barrel Thread Direction
CCW (Counter Clockwise)
Outer Barrel Thread Size
14mm
Inner Barrel Diameter
6.04mm
Inner Barrel Length
360mm

Magazine Specific

Magazine Type
Gas, Real Capacity,
Magazine BB Capacity
Approx. 30 Rounds
Magazine BB Fill Method
Speed Loader
Magazine BB Fill Location
Top
Magazine Gas Fill Location
Back
Magazine Gas Type
Green Gas

Gas Gun Specific

Gas Can Icon
Gas Compatability
Summer Gas, Green Gas, Red Gas,
Gas Can Icon
Gas Recommendation
Green Gas

Pistol Specific

Construction Icon
Slide Material
Steel
Icon Pistol Slide
Pistol Slide Type
Bolt Carrier

Product Testing Data

Notepad Icon
Test Description
350 FPS +/- 10%
Notepad Icon
Tested Using
0.2g ASG BLASTER & VORSK V6 Green Gas
Notepad Icon
Test Date
06/02/2024

Size guide

Joule Charts

Special Instructions

These table can be used as a reference to see if the BB weight you are using will be over acceptable Joulage limits at some Airsoft Sites in the UK. To check if the weight can be used chrono your weapon using the BB you intend to use, and then compare it to the chart.

FPS, Power and Joule Limits can vary from site to site, so please get in touch with where you're going to play with in advance to avoid disappointment.

Suggested limits are based on Joulage Limit rules used Halo Mill: Proving Grounds, with a 350fps limit for Automatic Replicas, 400fps for Semi-Automatic Replicas, and 500fps for Bolt Action Replicas.

Tap the tabs below to open the relevant chart for your replica.

Suggested limits are based on Joulage Limit rules used Halo Mill: Proving Grounds, and is the equivalent of 350fps, using 0.20g BB resulting in an upper limit of 1.14j.

Velocity BB Weight (Grams)
FPS 0.20 0.25 0.28 0.30 0.32 0.36 0.40 0.43 0.45 0.50
250 0.58 0.73 0.81 0.87 0.93 1.05 1.16 1.25 1.31 1.45
260 0.63 0.79 0.88 0.94 1.00 1.13 1.26 1.35 1.41 1.57
270 0.68 0.85 0.95 1.02 1.08 1.22 1.35 1.46 1.52 1.69
280 0.73 0.91 1.02 1.09 1.17 1.31 1.46 1.57 1.64 1.82
290 0.78 0.98 1.09 1.17 1.25 1.41 1.56 1.68 1.76 1.95
300 0.84 1.05 1.17 1.25 1.34 1.51 1.67 1.80 1.88 2.09
310 0.89 1.12 1.25 1.34 1.43 1.61 1.79 1.92 2.01 2.23
320 0.95 1.19 1.33 1.43 1.52 1.71 1.90 2.05 2.14 2.38
325 0.98 1.23 1.37 1.47 1.57 1.77 1.96 2.11 2.21 2.45
328 1.00 1.25 1.40 1.50 1.60 1.80 2.00 2.15 2.25 2.50
330 1.01 1.26 1.42 1.52 1.62 1.82 2.02 2.18 2.28 2.53
335 1.04 1.30 1.46 1.56 1.67 1.88 2.09 2.24 2.35 2.61
340 1.07 1.34 1.50 1.61 1.72 1.93 2.15 2.31 2.42 2.68
345 1.11 1.38 1.55 1.66 1.77 1.99 2.21 2.38 2.49 2.76
350 1.14 1.42 1.59 1.71 1.82 2.05 2.28 2.45 2.56 2.85
355 1.17 1.46 1.64 1.76 1.87 2.11 2.34 2.52 2.63 2.93
360 1.20 1.51 1.69 1.81 1.93 2.17 2.41 2.59 2.71 3.01

Suggested limits are based on Joulage Limit rules used at Halo Mill: Proving Grounds, and is the equivalent of 400fps, using 0.20g BB resulting in an upper limit of 1.49j.

Velocity BB Weight (Grams)
FPS 0.20 0.25 0.28 0.30 0.32 0.36 0.40 0.43 0.45 0.50
250 0.58 0.73 0.81 0.87 0.93 1.05 1.16 1.25 1.31 1.45
260 0.63 0.79 0.88 0.94 1.00 1.13 1.26 1.35 1.41 1.57
270 0.68 0.85 0.95 1.02 1.08 1.22 1.35 1.46 1.52 1.69
280 0.73 0.91 1.02 1.09 1.17 1.31 1.46 1.57 1.64 1.82
290 0.78 0.98 1.09 1.17 1.25 1.41 1.56 1.68 1.76 1.95
300 0.84 1.05 1.17 1.25 1.34 1.51 1.67 1.80 1.88 2.09
310 0.89 1.12 1.25 1.34 1.43 1.61 1.79 1.92 2.01 2.23
320 0.95 1.19 1.33 1.43 1.52 1.71 1.90 2.05 2.14 2.38
330 1.01 1.26 1.42 1.52 1.62 1.82 2.02 2.18 2.28 2.53
340 1.07 1.34 1.50 1.61 1.72 1.93 2.15 2.31 2.42 2.68
350 1.14 1.42 1.59 1.71 1.82 2.05 2.28 2.45 2.56 2.85
360 1.20 1.51 1.69 1.81 1.93 2.17 2.41 2.59 2.71 3.01
370 1.27 1.59 1.78 1.91 2.03 2.29 2.54 2.73 2.86 3.18
380 1.34 1.68 1.88 2.01 2.15 2.41 2.68 2.88 3.02 3.35
390 1.41 1.77 1.98 2.12 2.26 2.54 2.83 3.04 3.18 3.53
400 1.49 1.86 2.08 2.23 2.38 2.68 2.97 3.20 3.34 3.72
410 1.56 1.95 2.19 2.34 2.50 2.81 3.12 3.36 3.51 3.90

Suggested limits are based on Joulage Limit rules used at Halo Mill: Proving Grounds, and is the equivalent of 500fps, using 0.20g BB resulting in an upper limit of 2.32j.

Velocity BB Weight (Grams)
FPS 0.20 0.25 0.28 0.30 0.32 0.36 0.40 0.43 0.45 0.50
250 0.58 0.73 0.81 0.87 0.93 1.05 1.16 1.25 1.31 1.45
260 0.63 0.79 0.88 0.94 1.00 1.13 1.26 1.35 1.41 1.57
270 0.68 0.85 0.95 1.02 1.08 1.22 1.35 1.46 1.52 1.69
280 0.73 0.91 1.02 1.09 1.17 1.31 1.46 1.57 1.64 1.82
290 0.78 0.98 1.09 1.17 1.25 1.41 1.56 1.68 1.76 1.95
300 0.84 1.05 1.17 1.25 1.34 1.51 1.67 1.80 1.88 2.09
310 0.89 1.12 1.25 1.34 1.43 1.61 1.79 1.92 2.01 2.23
320 0.95 1.19 1.33 1.43 1.52 1.71 1.90 2.05 2.14 2.38
330 1.01 1.26 1.42 1.52 1.62 1.82 2.02 2.18 2.28 2.53
340 1.07 1.34 1.50 1.61 1.72 1.93 2.15 2.31 2.42 2.68
350 1.14 1.42 1.59 1.71 1.82 2.05 2.28 2.45 2.56 2.85
360 1.20 1.51 1.69 1.81 1.93 2.17 2.41 2.59 2.71 3.01
370 1.27 1.59 1.78 1.91 2.03 2.29 2.54 2.73 2.86 3.18
380 1.34 1.68 1.88 2.01 2.15 2.41 2.68 2.88 3.02 3.35
390 1.41 1.77 1.98 2.12 2.26 2.54 2.83 3.04 3.18 3.53
400 1.49 1.86 2.08 2.23 2.38 2.68 2.97 3.20 3.34 3.72
410 1.56 1.95 2.19 2.34 2.50 2.81 3.12 3.36 3.51 3.90
420 1.64 2.05 2.29 2.46 2.62 2.95 3.28 3.52 3.69 4.10
430 1.72 2.15 2.40 2.58 2.75 3.09 3.44 3.69 3.86 4.29
440 1.80 2.25 2.52 2.70 2.88 3.24 3.60 3.87 4.05 4.50
450 1.88 2.35 2.63 2.82 3.01 3.39 3.76 4.04 4.23 4.70
460 1.97 2.46 2.75 2.95 3.15 3.54 3.93 4.23 4.42 4.91
470 2.05 2.57 2.87 3.08 3.28 3.69 4.10 4.41 4.62 5.13
480 2.14 2.68 3.00 3.21 3.42 3.85 4.28 4.60 4.82 5.35
490 2.23 2.79 3.12 3.35 3.57 4.02 4.46 4.80 5.02 5.58
500 2.32 2.90 3.25 3.48 3.72 4.18 4.65 4.99 5.23 5.81
510 2.42 3.02 3.38 3.62 3.87 4.35 4.83 5.20 5.44 6.04