Echo1 General Assault Tool X (GAT) AEG Sub Machine Gun (GATX - JP129)

TEC-9 Iconography Meets Modern M4 Ergonomics

While standard submachine guns offer immense mobility, the lack of a shoulder stock can compromise accuracy during sustained full-auto bursts. The Echo1 General Assault Tool X (GATX) bridges this gap by marrying the aggressive TEC-9 open-bolt aesthetic with modern AR-15 ergonomics. Featuring a factory-installed M4 stock tube and collapsible multi-position stock, the GATX provides a stable shoulder weld without adding unnecessary bulk. With Quick-Detach (QD) sling mounting points built directly into the stock tube area, transitioning between primary and sidearm positions is effortless.

Full-Sized 8mm Gearbox Drivetrain

Do not let the submachine gun label trick you into expecting pistol-level performance. Inside the GATX is a true full-sized custom 8mm reinforced metal gearbox equipped with steel gears, a full-metal tooth piston, and a high-torque short-type motor.

Clocking in consistently at 330–350 FPS using 0.20g BBs, this SMG outperforms standard gas sidearms and easily holds its ground against full-sized assault rifles. The internal architecture is LiPo-ready straight out of the box, delivering crisp trigger response and a terrifying rate of fire on full-automatic.

Smart Battery Placement & Tactical Modularity

The GATX balances structural strength with tactical convenience. The upper receiver, outer barrel, sling loops, buffer tube, and magazines are constructed from durable alloy, while the lower chassis is molded from high-impact polymer.

The front vertical grip serves a dual purpose: providing an ergonomic indexing point for muzzle control while housing the battery compartment. Positioned beneath the barrel shroud is an integrated 20mm Picatinny rail section for mounting lights or lasers. Underneath the removable US factory orange tip, standard M14x1 CCW (14mm Counter-Clockwise) threads are available, making it simple to attach tracer units or mock suppressors for night-ops play.

Key Features at a Glance

• Adjustable M4 Buffer Tube & Stock: Multi-position collapsible crane stock provides superior shoulder stability and cheek weld.

• Hybrid Metal/Polymer Build: Metal upper receiver, barrel assembly, and stock tube paired with a high-impact polymer lower receiver.

• 8mm Custom Reinforced Gearbox: Full-performance metal gearbox delivers reliable 330–350 FPS velocity out of the box.

• Integrated Battery Foregrip: Vertical front grip houses the battery while serving as a steady control point.

• M14x1 CCW Muzzle Threading: Removable orange tip reveals standard 14mm CCW threads for tracer units and silencers.

• QD Sling Attachment: Built-in Quick Detach sling mounting points for fast gear integration.

• Dual Magazine Bundle: Ships with 2x ~250-round metal high-capacity magazines for heavy suppressing power.

• LiPo-Ready Architecture: Heavy-duty internal components handle standard LiPo battery setups with ease.

Technical Specifications

Package Includes

• 1x Echo1 General Assault Tool X (GATX / JP-129) AEG Sub Machine Gun

• 2x ~250-round High-Capacity Metal Magazines

• 1x Battery

• 1x Wall Charger

• 1x User Manual

Note on Barrel Threading: Distributed by US-based Jag Precision / Jag Arms, this replica comes with a factory orange tip. The tip can be carefully removed to expose the M14x1 CCW (14mm CCW) muzzle threads underneath for mounting mock suppressors or tracer units.

The Verdict

The Echo1 General Assault Tool X (GATX) takes everything players loved about the original GAT—its robust 8mm gearbox, TEC-9 styling, and dual magazine bundle—and solves the recoil stability issue by introducing a full M4 stock assembly. The result is a highly agile, shoulder-mounted CQB primary that offers rapid target transitions, heavy suppressing firepower, and out-of-the-box reliability.