KWA LM4D M-LOK Gas Rifle
The latest iteration of KWA’s LM4 series
The KWA LM4D M-LOK is a 6mm gas blowback airsoft rifle in the M4/AR-15 pattern and the latest version of KWA’s LM4 series. It runs on green gas, fires semi and full auto at 380–400 FPS from a 40-round magazine, and has a full metal body, an 8 lb trigger break, a tool-less dial hop-up and a 9.5-inch M-LOK handguard.
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What is the LM4D M-LOK?
Modeled after modern sporting and patrol rifles, the LM4D brings a major update in function and looks. The fixed front sight post is replaced with PTS flip-up sights for a clear sight picture with optics, and the 9.5-inch rail leaves plenty of room for lights, lasers and foregrips. The selector and charging handle are ambidextrous, and the minimalist buttstock has QD sling sockets on both sides.
Inside, the trigger now has an 8 lb break with moderate take-up and a heavier second stage. The legacy rotary hop-up is replaced by a tool-less dial hop-up, so you no longer need to remove the barrel assembly to swap the hop-up or bucking.
- 10.5-inch outer barrel
- 9.5-inch M-LOK handguard
- PTS Enhanced Polymer Back-Up Sights, front and rear
- PTS Enhanced Polymer Pistol Grip
- Ambidextrous charging handle and selector switch
- Minimalist buttstock with QD sockets on both sides
- 8 lb trigger break with a heavier second stage
- Tool-less dial hop-up and redesigned bolt face
LM4D M-LOK Features
Tool-less Hop-Up
Easily adjustable hop-up.KWA’s dial hop-up lets you fine-tune backspin for accuracy with any BB weight, without removing the barrel assembly.
Enhanced Gas Performance
Redesigned for reliability.KWA went back to the drawing board and revamped the bolt for better performance and a more dependable gas blowback system.
M-LOK Rail
Modern M-LOK rail.KWA’s rigid M-LOK rail is durable and sleek, with room for your attachments.
Full Metal Body
Durable construction.Built from high-quality metal for weight, durability and a premium finish.
QD Sling Sockets
Single-point ready.The minimalist buttstock has quick-detach sockets on either side for single-point sling attachment.
8 lb Trigger Break
Moderate take-up and a heavier second-stage break, a pull weight built for trigger-control training.
Ambidextrous Controls
The selector switch and charging handle are upgraded for ambidextrous use.
PTS Flip-Up Sights
PTS Enhanced Polymer Back-Up Sights fold away for an unobstructed view through optics.
LM4D quick start
LM4D quick start guide. Setup, filling magazines and first shots.
How to prime a gas magazine. Priming reduces air pockets for more consistent fills.
LM4D M-LOK Specifications
| Performance | |
|---|---|
| Power system | Gas blowback |
| Gas | Green gas |
| Velocity | 380–400 FPS |
| Rate of fire | 18+ rounds per second |
| Firing modes | Safe, semi-auto, full auto |
| Magazine capacity | 40 rounds |
| Hop-up | Tool-less dial hop-up |
| Trigger | 8 lb break, moderate take-up, heavier second stage |
| Dimensions | |
| Length | 29.25 in retracted, 32 in extended |
| Height | 8 in |
| Outer barrel | 10.5 in |
| Inner barrel | 11.75 in |
| Weight | 6.5 lb |
| Build | |
| Body | Full metal |
| Rail | 9.5-inch M-LOK handguard |
| Sights | PTS Enhanced Polymer Back-Up Sights, front and rear |
| Grip | PTS Enhanced Polymer Pistol Grip |
| Stock | Minimalist buttstock with QD sockets both sides, retractable |
| Compatibility | Mil-spec buttstocks and pistol grips |
| Controls | Ambidextrous charging handle and selector |
| SKU | 103-00219 |
What comes with the LM4D M-LOK
In the box
- LM4D M-LOK gas blowback rifle
- One KWA LM4 40-round magazine
- PTS flip-up back-up sights, front and rear
You will also need
- Green gas
- 6mm airsoft BBs
- Silicone oil for magazine seals
- Full-seal eye protection
Popular add-ons
- Spare LM4 40-round magazines
- LM4D Series AGM 40-round magazine with dry-fire function
- LM4 Magazine Repair Kit
- Home Range Kit – LM4D M-LOK for practice at home
How the LM4D M-LOK works
Gas blowback rifles reward a little know-how. Here is what to expect.
Gas blowback, explained
Green gas is stored in the magazine. Each trigger pull releases gas that fires the BB and drives the bolt back, which gives you bolt movement and recoil.
Because the gas lives in the magazine, healthy magazines mean a healthy rifle. Keep their seals oiled and fill them correctly.
Filling an LM4 magazine
Inspect the magazine first. If gas is still inside, release it with the valve at the top rear, and keep clear of the escaping gas.
- Hold the magazine upside down (floor plate up) and the green gas can upside down and vertical, with the fill needle pointing down.
- Fill for about 30–40 seconds. Listen for a faint hiss while it fills.
- Prime the magazine now and then by pressing the release valve as you first insert the fill needle. This reduces air pockets.
- Magazines get cold after shooting. A pouch or pocket helps them return to room temperature.
The 8 lb trigger
The LM4D trigger has moderate take-up and a heavier second-stage break at about 8 lb. That pull weight makes the LM4D a strong choice for training trigger control.
Hop-up, explained
Hop-up puts backspin on the BB so it lifts and flies flatter and farther. Too little and BBs drop early. Too much and they climb.
- Start with the hop-up at its lowest setting.
- Fire a few shots at a target at your usual distance.
- Add a little hop at a time until BBs fly flat before they drop.
- Back it off if BBs start to rise. Re-check whenever you change BB weight.
LM4D vs LM4D M-LOK
Same rifle, same internals. The difference is the handguard.
| LM4D (quad rail) | LM4D M-LOK | |
|---|---|---|
| Handguard | 9.5-inch TPR free-float quad Picatinny | 9.5-inch M-LOK |
| Best for | Mounting lots of Picatinny accessories | A slimmer, lighter-feeling handguard |
| Velocity | 380–400 FPS | 380–400 FPS |
| Magazine | 40 rounds | 40 rounds |
| Trigger | 8 lb break | 8 lb break |
| Weight | 6.5 lb | 6.5 lb |
LM4D M-LOK care and parts
- Inspect magazines before each use. Make sure feed lips are intact and free of cracks.
- Put a drop of silicone oil on the top of the magazine main seal, just behind the feed lips. It helps the magazine seal against the bolt carrier.
- Do not shake the gas can before filling, and avoid dropping magazines.
- Store green gas magazines in a cool, dry place and never in direct sunlight.
- Replace worn seals and O-rings as needed.
Common maintenance parts for the LM4D: bolt (#369), bolt base (#6001), bolt base return spring (#62), bolt base O-rings (E-22 small, E-24 large), magazine nozzle seal (#236), release valve (#240/246), charging valve (#245) and magazine lip (#230). See the Common Maintenance Parts tab on this page for direct links.
The operator manual, parts diagram and magazine diagram are in the KWA Resources tab, or in the Manuals & Diagrams library.
LM4D M-LOK FAQ
What is the KWA LM4D M-LOK?
A 6mm gas blowback airsoft rifle from KWA in the M4/AR-15 pattern, the latest version of the LM4 series, with a full metal body, 8 lb trigger, tool-less dial hop-up and a 9.5-inch M-LOK handguard.
How many FPS does the LM4D M-LOK shoot?
KWA lists the LM4D M-LOK at 380–400 FPS.
Does the LM4D M-LOK use green gas or CO2?
Green gas.
Which magazines fit the LM4D M-LOK?
It comes with one KWA LM4 40-round magazine. The LM4D Series AGM 40-round magazine also fits, and adds a dry-fire function for training.
What is the difference between the LM4D and LM4D M-LOK?
Only the handguard. The LM4D has a 9.5-inch free-float quad Picatinny rail and the LM4D M-LOK has a 9.5-inch M-LOK handguard. Internals and performance are the same.
How long should I fill an LM4 magazine?
About 30–40 seconds, with the magazine floor plate up and the can upside down. Listen for a faint hiss while it fills.
Can I change the stock and grip on the LM4D M-LOK?
Yes. KWA lists it as compatible with mil-spec buttstocks and pistol grips.
Can I pay for the LM4D M-LOK over time?
Yes. Choose Klarna at checkout to split it into 4 interest-free payments, or Affirm to pay over time. Both are subject to approval. See Payment Options.
Do I earn KWA Rewards points on the LM4D M-LOK?
Yes. KWA Rewards members earn 1 point for every $1 on orders of $50 or more, so the LM4D M-LOK earns about 510 points, worth $10.20 in store credit (50 points = $1). See KWA Rewards.
Is the LM4D M-LOK covered by a warranty?
Every KWA gun is backed by KWA, with warranty support and in-house service in California. Protection Plus adds extended warranty coverage and a repair plan with no repair fee, discounted parts and free return shipping. See the Protection Plus page for plan details.
