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King Arms Full Metal Fully Licensed Colt M4A1 Carbine Airsoft Gas Blowback GBB Rifle

ID: 33960 (GR-KA-M4A1)
KAGBB01 - 180552
Cybergun / Spartan Mil/LE806481185522KAGBB01 - 18055233960
4.5 stars, based on 14 reviews
King Arms Full Metal Fully Licensed Colt M4A1 Carbine Airsoft Gas Blowback GBB Rifle
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Rail system, optic, PEQ box, and vertical grip sold separately
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Cybergun / Spartan Mil/LEKing Arms / Eagle Force


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  • ATF approved full metal receiver with trade marks officially licensed by Colt
  • Compatible with most G&P and Western Arms parts, making the upgrade potential nearly limitless
  • Compatible with most aftermarket external accessories including many real steel parts
  • Highly realistic gas blow back system provides firearm like manipulation of this airsoft rifle
  • Adjustable ROF and FPS with included buffer shims and valve blockers for multiple types of play

FPS Range: 330-380

The King Arms Colt M4 is a fully licensed gas blow back M4 variant and bears highly appealing Colt trade marks on the receiver. The receiver of this M4A1 displays a highly realistic finish that closely resembles that of a real steel rifle. The King Arms Colt M4A1 uses a standard M4 Hand guard, LE Stock, and pistol grip making it perfect as it or a great base to build a tactical rifle. The possibility external upgrades is endless, from Magpul furniture to a full on rail system, the King Arms Colt M4A1 is a perfect platform for any build style. A M4 style carry handle with rear iron sight is included as well as a front triangle sight, both are adjustable for both elevation and windage on the fly. Additionally the King Arms M4A1 features a adjustable rate of fire which is fine tuned via spring buffers giving the user the choice of a realistic or high rate of fire . Also featured on this gun is a adjustable FPS system which utilizes valve blockers. One valve blocker is designed for high FPS with the other is for lower FPS. Shooting the King Arms M4A1 is sure to impress even the most critical of users. The bolt of the King Arms M4 provides a smooth and crisp cycling on manipulation and firing. The recoil provides an added sense of realism to airsoft due to the increase feel on each shot as well as the ability to lock the bolt after the magazine has been depleted. This GBBR is also compatible with most G&P and Western Arms parts, making the upgrade potential nearly limitless. The King Arms M4a1 GBBR is a sure-fire hit and is just begging to be the next addition to your collection. Whether you are looking to get into gas rifles for the first time or you are looking for a perfect platform for your next build, you are sure to be impressed.

*Being G&P & Western Arms 99% compatible. (Slight mod to meet US ATF requirements). This rifle offers tons of after-market custom parts and upgrade parts. Most of the exterior parts are 100% compatible and 99% of the internal parts are compatible. Check out our WA & WE gas blowback m4 custom parts section to customize your King Arms M4 GBB today!

Magazine Capacity: 50 Rounds. One included. Use all WA M4 / G&P M4 GBB compatible magazines.
(The GHK version magazine seems to not fit very well and would require modification to work, due to compatibility issues. Get KA or G&P for best compatibility and performance.)
Firing Mode: Semi Automatic, Full Automatic and Safety
Hopup: Adjustable
Weight: 2270g. (Without magazine).
Overall Length: 770mm (850 with stock extended)
Inner Barrel Length: 368mm. The King Arms M4 GBB uses AEG type tight bore inner barrels.
Gas: Green gas, propane adapter, co2 magazine.
System: Open bolt
Action: Gas blowback
Caliber: 6mm / High grade bbs recommended.
Muzzle Velocity: 330~380 FPS
Package Includes: Gun, Magazine
Firing Mode: Fully Automatic, Semi Automatic, Safety
Range: 70~140 feet
Materials: Aluminum, Nylon Fiber Polymer
Length: 770mm-850mm
Source of Power: Green Gas, Propane with adapter

Manufacturer: King Arms under license from Cybergun (Colt Trademark and Colt Logo are property of New Colt Holding Corp.)

About Cybergun / Spartan Mil/LE

Cybergun is the world leader in designing and distributing replica dummy weapons for video game aficionados, sport or outdoor shooting, and collectors.

About King Arms / Eagle Force

King Arms was founded in 2004 with the mission to ensure optimum customer satisfaction by providing precision products and outstanding service. In 2015, we moved our headquarters from Hong Kong to Taiwan where we've continued to provide excellent products with the highest quality. While working with leading firearms manufactures, we provide to our customers a level of innovation and authenticity that can't be found anywhere else in the Airsoft industry. This goal is what continuously drives us to improve and gives us purpose.

14 Customer Reviews

(Write a review)

by Patrick W. on 10/10/2017
"Okay. So I just received this rifle this morning. It comes with a large and small spring buffer, already installed; I took out the large and left the small in place for a realistic ROF and to enable the bolt lock. Also included are a magazine and basic speed loader.

As someone who has owned several high-end AR-15s, this GBB is the perfect airsoft weapon. 1:1 scale, aluminum receivers, carry handle and iron sights. It was like Christmas came early. Checked out the internals for any possible issues, found absolutely none whatsoever. This rifle has very tight tolerances. The magazine fits very tight in the magwell and definitely needs to be broken in. Weapon manipulation is just like the real thing and extremely satisfying.

As far as the magazine is concerned, it performs flawlessly. No leaks at all. I was skeptical of it after reading several poor reviews, however after testing it I am extremely happy and confident in using it.

I tested it outside, this afternoon, about 15 minutes ago. It was about 68 degrees and cool out. Fed it 5 magazines with .20s to test its reliability and accuracy. It is amazing right out of the box...I had only 1 jam on full auto, which was easily cleared in under 5 seconds. Accuracy is wonderful and I plan on further testing its capabilities. The fun switch and recoil is utterly amazing, and is quite the guilty pleasure!!!

I highly recommend this rifle!!! It is perfection, especially with the Colt licensing and trades; absolutely gorgeous...I'm am planning on upgrading the externals to either a SOPMOD Block I or II kit, not sure which yet...

"God made all men, but Samuel Colt made all men equal."
by Matt B. on 08/08/2017
"This is a great looking GBB Rifle with the best looking marking on the whole-wide world on it! COLT!!

Western Arms / G&P System - Easy to find spare parts and lots of upgrade parts
Bolt locks when mag empty
Easy to find spare mags
As real as it gets!
Good gas compression.


As a GBB nerd, I highly recommend this!
by Chris D. on 09/29/2016
"Great starter gun for GBB. Be aware though that GBBs generally need a little extra TLC than those sewing machine sounding AEGs.

Accuracy is top notch
FPS is adjustable
People get terrified when they hear you
Very real feel and realistic field stripping
Good hop-up
Removable top rail exposes a rail for a scope if you want to DMR

Gotta keep it lubed up
Magazines extremely prone to leakage
Firing automatic could risk a misfire and a broken loading nozzle (one of the only plastic parts of the gun)
This won't cooperate in cold weather

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