Daniel Defense DDM4 MK18 Law Tactical SBR, 5.56 NATO

Product Description

The Daniel Defense DDM4 MK18 Law Tactical SBR is a semi-automatic 5.56 NATO NFA short-barrelled rifle built on a 10.3" Government profile cold hammer forged barrel with a carbine-length gas system and the MK18 RIS II Picatinny quad rail, fitted with a Law Tactical folding stock adapter.

The folding adapter is why this SKU exists. It installs between the lower receiver and the receiver extension and lets the stock assembly hinge to the side, taking several inches off an already short rifle for storage and transport. Because the adapter changes both folded and extended dimensions, we are not publishing weight or overall length figures here — call 817-393-4000 and we will confirm them for this part number.

Underneath is the genuine MK18 pattern. The RIS II quad rail is the handguard Daniel Defense supplies to USSOCOM, with a patented bolt-up system tested before fielding, free floating the barrel and giving continuous Picatinny surface on four sides for night vision, lights and lasers. The 10.3" barrel is the length in service for the MK18 upper used for close-quarters work, and it is fed by a carbine-length gas system — the only practical option that short. Three Santoprene rail ladders, heat resistant to 300 degrees F, cover unused rail sections.

NFA short-barrelled rifle — what is required

This is a short-barrelled rifle regulated under the National Firearms Act. Possession requires a BATFE tax stamp and an approved NFA transfer completed through a dealer holding a Special Occupational Tax stamp. Western Sport is an SOT and handles NFA transfers routinely. This page does not give legal advice or timelines; call 817-393-4000 and we will explain how the transfer works through us and what we need from you. See our NFA firearms for related items.

Key Facts

• Brand / Model: Daniel Defense DDM4 MK18 Law Tactical
• Manufacturer Part Number: 02-088-09444-047 | UPC: 815604018357
• Legal category: NFA short-barrelled rifle (SBR)
• Action: Semi-automatic | Caliber: 5.56mm NATO
• Barrel: 10.3", Government profile, 1:7 twist, cold hammer forged
• Barrel material / finish: Chrome Moly Vanadium steel; chrome lined, Mil-Spec heavy phosphate coated
• Gas system: Carbine length
• Muzzle device: Daniel Defense flash suppressor, 17-4 PH stainless steel, salt bath nitride
• Muzzle thread: 1/2 x 28 TPI
• Rail: Daniel Defense MK18 RIS II, 6061-T6 aluminium, Type III anodized, Bolt-Up System
• Stock adapter: Law Tactical folding stock adapter
• Receivers: 7075-T6 aluminium, Type III hard coat anodized
• Bolt carrier group: M16 profile, MP tested, chrome lined, properly staked gas key
• Trigger: Mil-Spec
• Charging handle: Ambidextrous GRIP-N-RIP
• Other: Three Santoprene rail ladders, heat resistant to 300 degrees F; made in USA
• Weight and overall length: call 817-393-4000 — the folding adapter changes both

Who buys a folding SBR

People who need the rifle to fit somewhere specific: a pack, a discreet case, a vehicle console, an awkward safe. A folding adapter does not make the rifle shorter to shoot — it collapses the footprint when the gun is not in use. If you do not need that, a standard MK18 SBR is simpler. Compare the MK18 range we carry and browse optics.

Ordering from Western Sport in Roanoke, TX

Western Sport is a Daniel Defense master dealer in Roanoke, Texas, in business since 2007 with a gunsmith on site. Like every firearm this one must be transferred to a licensed FFL — and because it is an NFA short-barrelled rifle, that FFL must also hold an SOT, with an approved NFA transfer and tax stamp. We are both. Call 817-393-4000.

Frequently Asked Questions

Q: What does the Law Tactical adapter do?

A: It sits between the lower receiver and the receiver extension and lets the stock hinge to the side, collapsing the rifle’s footprint for storage and transport. On a 10.3-inch MK18 that makes an already short rifle notably more packable. It does not change how the rifle shoots.

Q: Does this MK18 require a tax stamp?

A: Yes. It is a short-barrelled rifle under the National Firearms Act, so possession requires a BATFE tax stamp and an approved NFA transfer through a dealer holding a Special Occupational Tax stamp. Western Sport is an SOT dealer; call 817-393-4000 and we will explain how the transfer runs through us.

Q: Why do you not list a weight or overall length for this rifle?

A: Because the folding adapter changes both, and we will not publish a figure that belongs to a different configuration. Call 817-393-4000 and we will confirm weight and folded and extended lengths for this exact part number before you order.

Q: What makes the MK18 RIS II rail different from a modern M-LOK rail?

A: It is a two-piece free-floating Picatinny quad with Daniel Defense’s patented Bolt-Up System, rigorously tested prior to fielding by USSOCOM. You get continuous rail surface on four sides for night vision and lasers, at the cost of more weight than an M-LOK handguard of the same length.

Q: Is the carbine gas system a compromise on a 10.3-inch barrel?

A: It is the only option that fits: there is no room for anything longer behind a 10.3-inch barrel. Port pressure runs high at this length, so the action cycles hard — normal here, and one reason many owners tune gas once a suppressor is fitted.

Q: Can I take delivery at your store?

A: Yes, once the NFA transfer is approved. Western Sport in Roanoke, Texas holds both an FFL and an SOT, so the tax-stamped transfer can be completed at our counter. Call 817-393-4000 and we will tell you exactly what we need and in what order.

Additional information