Colt M4 lower receiver with UID lable “M4 Carbine” marked

Colt M4 lower receiver, M4 Carbine marked with UID tag, complete – no stock

A genuine Colt M4 Carbine lower is already the right foundation for a serious M4-family clone. This version goes one step further with a serial-matched UID tag, adding the military inventory-control detail normally missing from commercial Colt lowers. You get the Colt pony, M4 CARBINE / CAL. 5.56 MM markings, CR-series serial, Colt internals and recoil system, plus a UID matched to the individual receiver. On an expensive clone, small details are often what separate “close” from convincing.

• Genuine Colt M4 Receiver — Real Colt forging, markings and serial-number series.
• Serial-Matched UID — Made for the individual receiver rather than using a generic serial.
• Military-Style Identification — CAGE, part number, serial and Data Matrix create the familiar issued-rifle appearance.
• Complete Colt Lower — Colt trigger and lower parts are already installed.
• Colt Recoil System — Factory receiver extension, heavy/H1 buffer and carbine spring.
• No Stock Included — Choose the stock appropriate to the M4, CQBR or SOPMOD configuration being built.

Why the UID Matters

The UID is more than a decorative square. DoD Item Unique Identification uses machine-readable marking to associate serialized equipment with identifying data for accountability and lifecycle tracking. On this lower, Charlie’s matches the UID to the receiver serial number, making the tag specific to that Colt lower rather than simply cosmetic.

One detail deserves explanation. The photographed UID carries CAGE 13629 and part number 12972700. U.S. Army documentation identifies 12972700 as the weapon-level part number for the M4A1 Carbine; the M4 is separately identified as part number 9390000. The receiver itself remains a commercial Colt M4 CARBINE-marked lower and is not represented as a U.S. Government-property M4A1 receiver.

That distinction is why this configuration is interesting. It delivers a genuine Colt M4 lower with the visual language of the military UID system, without stepping up to the scarcer “PROPERTY OF U.S. GOVT” M4A1 lower.

These are Colt factory rifle take-offs, not virgin receivers. Colt assembled and test-fired the donor rifle before the lower was separated. The lower includes Colt fire-control and lower parts, carbine receiver extension, heavy/H1 buffer and carbine spring. The stock is omitted so you can finish the clone with the correct furniture instead of paying for a stock you would replace anyway.

Technical Specifications

Manufacturer	Colt
Type	Complete M4-pattern lower receiver
Receiver Marking	M4 CARBINE / CAL. 5.56 MM
Serial Series	CR
Receiver Material	7075 forged aluminum
Finish	Black anodized
Fire Control	Colt semi-automatic trigger group
UID CAGE	13629
UID Part Number	12972700
UID Serial	Matched to receiver serial number
Receiver Extension	Colt 4-position carbine
Buffer	Colt heavy / H1
Action Spring	Carbine
Pistol Grip	Colt A2-pattern
Stock	Not included
Receiver Origin	Colt factory rifle take-off; factory test-fired
Virgin Lower	No — rifle-origin receiver
Transfer	Serialized firearm; FFL required
Manufacturer Part Number	Not separately published for this configuration