Mil-Spec M16A1 Lower - Stripped "Hydra-Matic" Clone Receiver - Gray Anodized

A stripped mil-spec lower receiver with decorative "GM Hydra-Matic / Property of US Government" clone markings, gray-anodized for the Vietnam-era M16A1 look — manufactured by BAD, LLC in a small batch run for Charlie's Custom Clones.

• Clone-style M16A1 rollmark with "GM Hydra-Matic" and "Property of US Government" engraving — decorative only
• Vietnam-era gray anodize — a special small-batch finish meant to echo the gray hardcoat seen on period M16A1 receivers
• 7075-T6 forged aluminum, A2/M4 geometry — a modern mil-spec lower that accepts any standard AR-15 lower parts kit
• Semi-auto only — three-position selector markings are cosmetic; the "AUTO" position is decorative and the lower is incapable of full-auto operation
• Virgin stripped lower — can be built into a rifle or pistol configuration

GM Hydra-Matic was one of three US manufacturers that produced M16A1 rifles during the Vietnam War, alongside Colt and Harrington & Richardson, with production spanning the late 1960s and 1970s. Original Hydra-Matic rollmarks are a coveted marker on a true Vietnam-era A1 clone, and authentic Hydra-Matic receivers are effectively impossible to source in usable condition today. This lower gives retro builders the visual cue — the Hydra-Matic rollmark and period-gray finish — without pretending to be an original Vietnam receiver.

For the purists: this is not a true A1 lower. It is a modern A2/M4-pattern forged lower that BAD, LLC produced with clone rollmarks applied by Charlie's specification. The differences between a late-model A1 lower and an A2 lower are real but subtle — the buffer-tube boss geometry and the takedown detent area being the most noticeable — and a careful collector will see them. The product is sold on that basis. For a retro build where the buyer wants the Hydra-Matic visual and a correct gray finish without paying original-receiver prices, this is the lower.

BAD, LLC's required ATF manufacturer markings are laid in minimally in the trigger area, which keeps the A1 clone rollmark visually clean from the left side. Charlie's does not repeat the serial number on the left side, to avoid any confusion about the actual manufacturer of the receiver.

Specifications

• Material: 7075-T6 forged aluminum
• Configuration: Stripped, semi-auto
• Geometry: Mil-spec A2/M4 lower
• Finish: Gray hardcoat anodize (special-order batch)
• Rollmarks: "GM Hydra-Matic" / "Property of US Government" — decorative clone engraving
• Manufacturer of record: BAD, LLC
• Parts compatibility: Accepts any standard AR-15 lower parts kit

One builder note: BAD produces these with intentionally tight takedown and pivot pin holes — they prefer a rattle-free rifle. You may need to dress your pins lightly to fit. That is by design, not a defect.

This is a serialized firearm receiver and must ship to a licensed FFL holder. No civilian exceptions.

1. Verify your state permits the receiver before ordering.
2. Have your FFL email a copy of their license to Charlie's — ask them to do the legwork; that's what the transfer fee is for.
3. Expect our compliance team to reach out within 3–4 business days. If you haven't heard, reach out for a status update.

California residents: the process differs under state law — please review our California firearms processing page before ordering.

We run small batches on parts like this because the anodizing and rollmark work is not cost-effective at volume. When they're gone they're gone. Grab one while they're here.