Mk18 Mod 0 complete lower receiver from FN

A limited-production FN 15 complete lower receiver with a custom Mk18 Mod 0 Crane-logo engraving on the left magwell — a clone-correct lower for a Mk18 Mod 0 build, assembled with FN factory lower parts and a six-position mil-spec buffer tube.

• Clone-correct Mk18 Mod 0 lower: FN-assembled receiver with a Charlie’s-commissioned Crane-logo engraving matched to period photographs of Crane-issued Mk18 Mod 0 rifles.
• FN factory lower parts kit: military-grade trigger and internals installed at the FN factory — the same LPK used on FN’s contract M4 work.
• Forged 7075-T6 aluminum receiver with hardcoat black anodizing.
• Six-position mil-spec buffer tube with carbine buffer, spring, staked castle nut, and mil-spec end plate.
• Take-off from a complete FN rifle — test-fired only at FN. Cannot be legally built into a pistol.

The Mk18 Mod 0 is the first-generation Naval Special Warfare CQBR, fielded from NSWC Crane beginning in the early 2000s. Its defining external feature is the KAC RIS rail; its defining receiver-level detail is the Crane-applied rollmark on the lower receiver magwell, which is what this engraving reproduces. FN, Colt, and LMT are the three primary contract manufacturers of M16-family rifles for U.S. forces; FN lower parts are essentially identical to Colt M4 military-grade lower parts prior to Colt’s 2020 Carbine release, which means the feel, break, and fit of this lower match a period-correct Mk18 Mod 0.

Because the lower is a take-off from a full FN rifle, it cannot be reconfigured into a pistol under current ATF guidance — it ships and remains classified as a rifle receiver. No stock is included; builders typically pair this lower with a B5 Bravo stock for a period-appropriate Mod 0 finish, or a Crane stock for the most common issued configuration.

Specifications:

• Receiver: FN factory-assembled FN15 forged 7075-T6, hardcoat anodized
• Engraving: Mk18 Crane logo on left magwell (Charlie’s custom)
• Trigger: FN factory mil-spec
• Buffer tube: Six-position mil-spec with carbine buffer and spring
• Castle nut: Staked, with mil-spec carbine end plate
• Grip: FN factory A2, black
• Stock: Not included
• Legal status: Rifle receiver (not convertible to pistol)

We researched the Crane-issued Mk18 Mod 0 rollmark against period photos before commissioning the engraving, because a Mk18 clone lives or dies on details like this. Order yours today and we’ll get it out the door. This item must ship to an FFL holder. No civilian exceptions.