Specna Arms SA-C20 CORE™ Gen.2 M4/AR-15 AEG

Specna Arms
Code: SPE-01-047113-00
2,329.00 kr
  • CNC Aluminium handguard
  • 6.03mm Tightbore inner barrel
  • Gen.2 - Magnus™ HOP-up, Aether™ gearbox shell

If you're looking for a highly flexible M4/AR-15 platform, the Specna Arms SA-C20 CORE™ HAL¹ ETU™ M4/AR-15 Carbine AEG should suit you perfectly! Kitted out with some glorious externals with a skeletonised M-LOK handguard, crane stock and railed receiver, this M4 is a great choice for any skirmisher! This, the latest version of the SA-C20, has been revamped to "Gen.2" internal standards, meaning more bang for your buck than ever before!

Specna's CORE™ Gen.2 pushes the featureset of affordable AEGs up a notch or two, equipped with the Aether™ enhanced gearbox shell and Magnus™ TDC Rotary HOP-up unit from the PRIME™ series. Also on board is the Aether™ CNC aluminium nozzle and Helium™ HOP-up bucking, boosting accuracy and range considerably. The HAL programmable ETU is the icing on the cake, offering a wide range of programmable fire modes, from 3-round burst to binary trigger, semi-auto only and much, much more!

Also present is Specna's usual 6.03mm tightbore inner barrel, polymer piston with full steel tooth rack and ESA quick-change spring system, making power tuning a breeze. If you need a mid-length platform with a high-quality yet lightweight build ready for any challenge on the field, the Specna Arms SA-C20 CORE™ Gen.2 M4/AR-15 AEG is the way to go!

Full description

Description

If you need a modern M4 platform, ready for any situation, then the Specna Arms SA-C20 CORE™ Gen.2 M4/AR-15 AEG is one to keep an eye on. Constructed to Specna's CORE™ standard, the SA-C20 boasts a CNC aluminium handguard and alloy outer barrel paired with a high-density polymer receiver, buffer tube, stock and pistol grip, giving you a great combination of realism and ease of use. As with the original CORE™ series, the polymer quality is much more scratch-resistant than comparable metal receivers and ultra-light for high energy throughout the skirmish day.

Inside this, the latest SA-C20 variant, known as the "Gen.2", we are treated to the advanced AETHER™ gearbox shell and Magnus™ TDC HOP-up unit of Specna's PRIME™ series, providing enhanced long-range performance and making gearbox tuning a piece of cake. Also inside is the HAL™ ETU/MOSFET, offering binary trigger, AUG mode and sniper delay instead of semi-auto and semi-auto lock, 3-round burst or 5-round burst instead of full auto, along with several quality-of-life improvements and most importantly for CQB, adjustable pre-cocking. Pre-cocking positions the piston at the rear of its cycle after a shot, meaning when you pull the trigger, the response is practically instantaneous, ideal for semi-auto duels in the close confines of a CQB site.

A considerable improvement over the original SA-C20, the Gen.2 enhancements add a lot of functionality to this lightweight player-friendly platform. With no more trigger lock-ups when shooting semi-auto, plenty of fire mode options and the pre-installed 6.03mm tightbore inner barrel and Magnus rotary HOP-up combo, the CORE™ Gen.2 line provides more bang for your buck than ever before!

Starting at the front, we find an M4-style Bird Cage flash hider attached to the outer barrel, which sticks out from the front of the CNC aluminium quad-railed handguard. This gives the SA-C20 a classic military look and replicates the real steel platform perfectly. The outer barrel features the common 14mm CCW male threading, ideal for swapping to a sneaky suppressor or tracer unit.

The handguard itself is constructed from CNC-machined aluminium, guaranteeing a flawless form and precise, in-spec attachment interfaces. A 20mm Picatinny rail is present at the 12 o'clock position, with an M-LOK interface present on the sides of the handguard. This platform is ready for both 20mm and M-LOK rail-compatible accessories, including grips, lasers, flashlights and more!

Next up, we reach the receiver, which is of a standard and instantly recognisable as the standard M4/AR-15 configuration with controls laid out in a considerate and ergonomic manner, allowing the SA-C20 to be manipulated quickly and instinctively by veterans or learned rapidly by new users.

The fire selector lever is situated just above the pistol grip, on the left side of the AEG, providing 3 modes of fire, SAFE, SEMI, and AUTO, with a 90-degree throw between each. The fire modes are helpfully marked in bold recessed text on the receiver, and the selector switch locks positively into each mode with the help of texture on its surface to guarantee you have a good grip on this control. The magazine release is on the right side of the magazine well, easily accessible for a right-handed user with the tip of the trigger finger, but can also be learned by a lefty using their off-hand thumb.

Pulling back the extended charging handle, at the top rear of the receiver, will open the dust cover and retract the mock bolt carrier, which allows access to the rotary HOP-up adjuster. This is the latest and greatest HOP-up design for the M4/AR-15 AEGs and provides finer increments of adjustment and holds its setting more effectively when compared to the older gear-style HOP-up unit. The charging handle has an extended latch for easier access, allowing even gloved users to access the HOP-up unit, though you may need to remove your glove to adjust the unit!

The bolt catch on the left side of the receiver does not function, but is nonetheless a separate part, mitigating the common tell-tale signs of a replica. The forward assist is a similar story, being present on the right side of the upper receiver and being a separate moving part which can be pressed in but does not affect the function of the AEG. A new addition to this HAL-equipped SA-C20 is the flat trigger, enhancing the aesthetic with a touch of modernity and providing an easily slappable trigger for snappy double taps in semi-auto.

The pistol grip of the SA-C20 is an M16A2/M4A1 style pistol grip, also known as the "A2" finger ridged grip. The A2 has diamond checkering on either side and linear texture on the back strap to provide excellent gripping qualities no matter the weather or whether you wear gloves or not. The finger ridge is designed to help you keep hold of the rifle and prevent the grip from slipping out of your hands when held in a single hand (if you're going for a Terminator-esque look). As with most M4/AR-15 AEGs, this grip is compatible with aftermarket M4/AR-15 AEG grips, ideal for customisation addicts!

The battery compartment is inside the crane stock, accessible by squeezing the two tabs at the toe of the stock together, after which you can lift the butt plate off, remove the battery plug and make use of the stock's built-in battery compartment to house a chunky nunchuck/crane-style battery. Being equipped with the HAL ETU, we are also treated to a Deans/t-plug battery connector, a lower resistance alternative to the mini-Tamiya found on previous Specna Arms CORE AEGs. For the SA-C20, we recommend a 7.4V 1300mAh LiPo crane/nunchuck battery for an easy fit and great performance.

The Crane stock also includes a pair of QD sling sockets, one on each side, allowing for QD sling swivels to be added for a quick, removable sling setup. Conventional sling slots (aka "footman loops") are also present for those who want a two-point sling but prefer the old-fashioned way. The butt plate is also made from grippy rubber, ensuring your SA-C20 doesn't slip off your shoulder at a critical moment.

Inside the Gen.2 SA-C20, we are treated to the Aether enhanced gearbox shell, the same reinforced V2 shell used in Specna's top-tier PRIME series. The Aether features a reinforced spine and ports throughout the design to allow for easy tuning, ideal for the techy types. Also inside are 18:1 ratio steel gears running on 8mm bushings. The spring guide is an ESA quick change example, making power tuning a breeze for those who want to get as close to site limits as possible. The inner barrel is a 6.03mm tightbore paired with the Magnus TDC rotary HOP-up unit, giving you superb accuracy potential and the most up-to-date HOP-up unit style for M4/AR-15 AEGs. All internal parts are Tokyo Marui AEG spec, meaning aftermarket upgrades are a go for the performance seekers!

The HAL¹ ETU adds a whole lot of functionality into the mix, with programmable fire controls, 6 levels of pre-cocking adjustment and 5 levels of trigger sensitivity adjustment. Available fire modes include 3 or 5-round burst, binary trigger, AUG mode aka two-stage trigger, semi-auto only and sniper delay, giving you loads of options for how you use your SA-C20. Features like these are usually only present in high-end replicas; we simply cannot believe the wealth of functionality inside the HAL¹-equipped SA-C20 Gen.2, especially considering the price!

If you want a platform that can do it all, then the Specna Arms SA-C20 CORE™ Gen.2 M4/AR-15 AEG is the one for you! This very versatile platform has plenty of rail space and is appropriate for both CQB and outdoor skirmishes. It packs amazing tech inside at a very attractive price point, especially considering its recent upgrade! The SA-C20 is perfect for new players to get started, or pros who are looking for a very high-tech AEG without the usual high price point.

Features

  • 6.03mm Tightbore inner barrel - Great accuracy potential
  • High-density polymer with CNC Aluminium handguard
  • Bird cage Flash Hider pre-installed - The iconic M4/M16 muzzle device
  • 14mm CCW Male threaded outer barrel - Tracer/suppressor ready
  • M-LOK handguard - Picatinny rail at 12 o'clock, M-LOK slots at other positions
  • QD Sling sockets on the handguard & stock - Ready for QD sling swivels
  • Flip-up aperture iron sights pre-installed - Adjustable for windage and elevation, 2 apertures to choose from
  • 20mm Picatinny railed receiver - Ready for red dot sights, PEQ lasers or scopes to be mounted
  • Rotary adjustable HOP-up unit - The latest M4/AR-15 design, holds its setting well and allows for fine adjustment
  • Finger-ridged "A2" pistol grip - Comfortable for most hand sizes, textured for extra traction
  • Flat mil spec trigger guard - Matches real US Army-issued M4A1 rifles
  • 3-Position fire selector switch - SAFE, SEMI AUTO & FULL AUTO, 90-degree throw between each mode
  • Extended charging handle - Fast access to the HOP-up unit for quick mid-game adjustment
  • 6-Position M4/AR-15 buffer tube - Adjust the stock quickly and easily to suit your body type or loadout
  • Crane stock pre-installed - Plenty of battery space, QD sling sockets built-in
  • Version 2 Gearbox:
    • Aether Enhanced gearbox shell
    • Aether Aluminium nozzle
    • Polymer piston with steel tooth rack
    • 8mm Bushings
    • ESA quick-change spring system
    • Steel 18:1 ratio gearset
  • HAL¹ Programmable MOSFET/ETU functions:
    • 3 or 5-round burst
    • Binary Trigger
    • Semi-auto only
    • Sniper delay
    • Two-stage trigger (AUG mode)
    • Adjustable pre-cocking (6 levels)
    • Active braking
    • Low voltage alarm
  • HAL¹ Programming instructions available here
  • Rear wired: Deans battery connector - Recommended battery: 7.4V 1300mAh LiPo in crane/nunchuck config.
  • Compatible with M4/AR-15 AEG magazines - S-Mag High-cap | S-Mag Mid-cap | S-Mag Mid-cap 5 Pack

Package Includes

  • Specna Arms SA-C20 CORE™ Gen.2 M4/AR-15 AEG
  • 125rnd S-Mag M4/AR-15 Mid-cap magazine x 2
  • Speedloader
  • Cleaning rod

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, using 0.20g BB
Approx.315fps ± 10%, using 0.20g BB
Site Legal Icon
Site Legal, using 0.20g BB
Yes
Screwdriver Icon
Pre-Built
Yes
Package
Included Items
  • Speed Loader
  • Magazine x 2
Skill Level Icon
User Skill Level
Regular Player
Patrol Base - Warning Icon
Warnings
Li-Po
Li-Po - Never Leave Charging Unattended
Li-Po - Only Use Approved Chargers
Li-Po - Charge in a Fire Safe Area

Weight and Dimension

Weight KG Icon
Weight (KG)
Approx. 2.11kg
Weapon Length Collapsed
Length (Collapsed)
74cm
Weapon Length Extended
Length (Extended)
83cm

Construction

Colour Wheel Greyscale
Primary Colour
Black
Construction Icon
Construction
CNC Aluminium handguard. Alloy flash hider, outer barrel & trim parts. High density polymer stock, buffer tube, receiver & pistol grip. Steel dust cover, pins and screws.
Weapon Construction External
External Construction
Polymer
Alloy
Rubber
Aluminium
Steel
Gearbox Icon
Internal Construction
Polymer
Alloy
Aluminium
Steel
Brass

Weapon Specific

Power Source Icon
Powered By
Electric
Blowback Icon
Blowback
None
Weapon Platform
Weapon Platform
Assault Rifle, M4 / AR-15 / M16, M4/AR-15 AEG,
Magazine Style Icon
Magazine Style
Long Gun Magazine, Assault Rifle, M4 / AR Platform,
Fire Select Icon
Fire Selector
PatrolBase | Fire Select Safe
Safe
Patrol Base | Fire Select - Semi Automatic
Semi Automatic
Patrol Base | Full Automatic
Full Automatic
Programmable
Weapon Safety Features Icon
Safety Features
Trigger Disconnect
Shooter Configuration Icon
Shooter Configuration
Right Handed
Weapon Configuration Icon
Weapon Configuration
Standard
Weapon Scale Icon
Weapon Scale
1:1
Suggested BB Weight
Suggested BB Weight
0.25g

Hop-Up

Hop-Up Unit Icon
Hop-Up Unit
Yes
Hop-Up Unit Adjuster Icon
Hop-Up Adjuster
Rotary
Hop-Up Unit Location Icon
Hop-Up Location
Behind the mock bolt carrier, accessible through the mock ejection port when the charging handle is pulled and held back.

Furniture

Weapon Furniture Icon
Furniture
  • Railed Handguard
  • Railed Receiver
  • Finger Ridged Pistol Grip
  • AR Buffer Tube
  • Sliding Stock
  • Flip-Up Ironsights
  • Bird Cage Flash Hider
  • Threaded Outer Barrel
  • QD Sling Point
  • Extended Charging Handle
  • sling points front and rear
  • Sling point on stock
  • Flat trigger
  • M-LOK Handguard
  • M-LOK Picatinny rails x 3
  • Rubber butt plate
Rail System Icon
Rail System
Pre-installed 20mm Picatinny rail sections for M-LOK, 20mm Railed Receiver, M-LOK,
Icon Stock Positions
Stock Setting
Sliding, Multi-Position, M4 Crane Stock,
Weapon Length Extended
Stock Positions
6 Position
Sight Type Icon
Sight Type
Iron Sights, Aperture Iron Sight,
Sling Plate Icon
Sling Options
Stock, Handguard, QD, Loop,

Barrel

Outer Barrel Length (in)
12''
Icon Thread Type
Outer Barrel Thread Type
Male
Icon Thread Direction
Outer Barrel Thread Direction
CCW (Counter Clockwise)
Outer Barrel Thread Size
Outer Barrel Thread Size
14mm
Inner Barrel Diameter
Inner Barrel Diameter
6.03mm
Inner Barrel Length
Inner Barrel Length
320mm

Magazine Specific

Magazine Type
Magazine Type
AEG, Medium Capacity,
Magazine BB Capacity
Magazine BB Capacity
Approx. 125 Rounds
Magazine BB Fill Method
Magazine BB Fill Method
Speed Loader
Magazine BB Fill Location
Magazine BB Fill Location
Top

Electric Gun Specific Information

Gearbox
Gearbox Icon
Gearbox Version
V2 Gearbox
Wiring Icon
Gearbox Wiring
Rear Wired
Spring Change Icon
Gearbox Quick Change Spring
Yes
Digital Trigger Icon
Gearbox Electronic Trigger
Yes
Motor
Airsoft Motor Icon
Motor Type
Standard
Battery Specific
Battery Connector
Battery Connector
Deans To Mini Tamiya
Deans To Mini Tamiya Adaptor
,
Patrol Base | Icon | Deans
Deans
,
Compatible Battery
Compatible Battery Type
Compatible Battery Type
Li-Po
Compatible Battery Configuration
Compatible Battery Configuration
Crane
Compatible Battery Voltage
Compatible Battery Voltage
7.4v

Product Testing Data

Notepad Icon
Test Description
315 FPS +/- 10%
Notepad Icon
Tested Using
0.20g Delta Armory Diamond BBs
Notepad Icon
Test Date
12/08/2025

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