KS-1 British Service in Airsoft

The KS-1, officially designated as the L403A1 in British service, is a modern assault rifle developed by Knight’s Armament Company (KAC). It was adopted by the British Armed Forces in 2023 under Project Hunter to enhance the capabilities of specialized units, including the Ranger Regiment and elements of the Royal Marines Commandos.

DESIGN AND FEATURES

• Barrel: The KS-1 features a 13.7-inch (34.8 cm) cold hammer-forged, heavy-profile barrel with distinctive ball-mill dimpling. This design reduces weight and minimizes heat-induced barrel shift.

• Calibre: Chambered in 5.56×45mm NATO, the rifle balances effective range with manageable recoil.

• Weight and Length: The KS-1 weighs approximately 6.88 lbs (3.12 kg). Its length ranges from 32.2 inches (81.8 cm) with the stock collapsed to 34.2 inches (86.9 cm) when extended.

• Gas System: Utilizing a direct gas impingement system, the KS-1 ensures reliable cycling and reduced recoil.

• Ambidextrous Controls: The rifle’s lower receiver is fully ambidextrous, featuring mirrored fire control safety, magazine release, and bolt catch/release on both sides, accommodating both left- and right-handed shooters.

• Handguard: Equipped with KAC’s proprietary free-floating URX 6 handguard, the KS-1 provides ample space for accessory attachment and protects the barrel from potential damage.

ADOPTION AND DEPLOYMENT

In September 2023, the UK Ministry of Defence announced the selection of the KS-1 as the L403A1 Alternative Individual Weapon (AIW) system. An initial order of 1,620 rifles was placed, with the potential to procure up to 10,000 units over the next decade. This decision aims to replace the existing L85A2/A3 and L119A1/A2 rifles in service with specialized British Army and Royal Marines units.

The L403A1 AIW system includes the rifle itself, a signature reduction system (suppressor), and an advanced optic system. The optic suite comprises a Vortex 1–10x low-power variable optic combined with an Aimpoint ACRO P-2 red dot sight, enhancing target acquisition and engagement capabilities.

The KS-1’s adoption signifies a significant modernization of the British Armed Forces’ small arms, providing troops with a versatile and reliable platform suited for diverse operational environments.

For a closer look at the KS-1 in action, you might find this video informative:

As of February 2025, the airsoft community has shown significant interest in replicating the Knight’s Stoner 1 (KS-1), also known as the L403A1 in British military service. While no major airsoft manufacturers have released an official KS-1 replica, enthusiasts have undertaken custom builds to emulate this rifle.

CUSTOM BUILDS

Airsoft hobbyists have been modifying existing platforms to mirror the KS-1’s aesthetics and functionality. A popular base for such projects is the VFC SR16E3 Mod2 gas blowback rifle, chosen for its close resemblance to the KS-1. Builders often replace the standard handguard with a 13-inch URX4 M-LOK handguard from Airsoft Artisan to match the KS-1’s design. Additional modifications include installing a 50mm outer barrel extension and custom suppressors to achieve the correct barrel length and appearance. These projects can be intricate and may require advanced technical skills. For detailed insights into such a build, you can refer to this Reddit discussion:

CONVERSION KITS

For those seeking a more straightforward approach, conversion kits are available. Angry Gun offers a KS1 Limited Deluxe Version MWS Conversion Kit compatible with the Tokyo Marui MWS gas blowback series. This kit includes:

• CNC aluminium upper and lower receivers styled after the KS-1

• A CNC aluminium URX6-style handguard

• Cerakote Magpul FDE coating for an authentic finish

• A CNC aluminium outer barrel with a steel gas tube set

• A QDC/MCQ-PRT dummy suppressor with a steel flash hider

This kit allows users to transform their existing Tokyo Marui MWS rifles into KS-1 replicas with relative ease. More information can be found here:

COMMUNITY DISCUSSIONS

The airsoft community actively shares knowledge and experiences related to KS-1 builds. Forums such as the Airsoft Forums UK feature discussions where members showcase their custom KS-1 projects, exchange tips, and provide guidance on sourcing parts and achieving accurate replicas. Engaging with these communities can offer valuable insights and support for your build.

HOW CLOSE CAN JBBG GET TO THE KS-1?

At Just BB Guns, we have several Airsoft Guns that can get close to the look and dimensions of the KS-1 in AEG and Gas Blowback. The nearest, we think, is the outstanding Nemesis Gen1 LS12 from Classic Army. By simply swapping out the stock and fitting a silencer, you will have a very close replica of the KS-1. Take a look for yourself… Nemesis Gen2 LS12 M4 AEG Carbine Airsoft Gun Classic Army.

HOW CLOSE CAN JBBG GET TO THE KS-1?

At Just BB Guns, we have several Airsoft Guns that can get close to the look and dimensions of the KS-1 in AEG and Gas Blowback. The nearest, we think, is the outstanding Nemesis Gen1 LS12 from Classic Army. By simply swapping out the stock and fitting a silencer, you will have a very close replica of the KS-1. Take a look for yourself… Nemesis Gen2 LS12 M4 AEG Carbine Airsoft Gun Classic Army.

ABOUT THIS BLOG

Address: Just BB Guns, Trimex House, Pier Road, Feltham, TW14 0TW
Call: 0330 900 5224
Website: www.justbbguns.co.uk
E-mail: [email protected]
Blog Title: KS-1 British Service in Airsoft
Blog Author: Mark Watts