Geissele lower receivers are the correct starting point for any clone-correct URGI or MK18 build. Built from 7075-T6 aluminum forgings, hard-anodized to MIL-A-8625 Type III, and machined to the dimensional tolerances that SOCOM specifications require, a genuine Geissele lower receiver is not a substitute — it is the part that the military contract calls for when the build needs to be right.
At Charlie's Custom Clones, we stock the complete Geissele lower receiver lineup because clone-correct starts with correct parts. The Geissele Super Duty stripped lower receiver is the baseline for both the URGI and the Super Duty complete rifle family. If you are building a clone of the USASOC URG-I as deployed starting in 2019, or the MK18 CQBR configuration fielded by NSW and Marine Raiders, the correct lower receiver is the Geissele Super Duty — and that is what you will find on this page.
For builders who want to move faster, we also carry the Geissele complete lower — fully assembled with the correct mil-spec fire control group, buffer assembly, and Geissele-spec stock configuration. Drop it under a clone-correct URGI or MK18 upper and the build is functionally complete without sourcing additional components.
Every Geissele lower for sale on this page is a genuine Geissele Automatics product. We source directly, verify the forge marks and hard-anodize, and ship from our shop in the United States. If you need help selecting the right configuration — stripped vs. complete, Super Duty vs. receiver set — the spec notes on each product page list the exact fielded variant the lower corresponds to.
The Geissele Super Duty stripped lower is the right choice if you are building the upper yourself or pairing with a specific upper assembly from CCC. Start stripped when clone-correctness requires sourcing your own lower parts kit (LPK), pistol grip, or stock to match a specific unit configuration. The stripped lower is also the right base if you want a Super Duty lower paired with a BCM or Colt MK18 upper — it gives you the correct foundation without locking you into a complete lower configuration.
The Geissele complete lower is the right choice when you want to minimize build time. Geissele assembles it to their own spec, which aligns with the URGI fielded configuration. Drop it under any clone-correct upper and you are done.
The USASOC URG-I uses the Geissele Super Duty lower receiver in the Black (standard) or DDC (desert) finish depending on deployment configuration. The lower pairs with the Geissele MK16 M-LOK railed URGI upper. If you are building the URGI impression, use the Super Duty stripped lower with the Geissele-spec LPK and the B5 SOPMOD stock. Full build details are in the product notes.
All Geissele lower receivers listed below are in stock and ready to ship. Filter by finish — Black, DDC, ODG, or Iridium — using the sidebar. Questions about pairing with a specific upper or completing a particular clone build? Contact us — we build these every day and can confirm the correct configuration before you order.
Pair your Geissele lower with a clone-correct upper from our URGI upper receivers page, or browse MK18 complete uppers for CQB configurations. For a ready-to-shoot option, see our clone-correct complete rifles.