MPN: 55BA290-AB


  • Fully assembled with ZEROED Polymer Dust Cover
  • Full Mil-Spec 1913 Picatinny top rail
  • M4 feed ramps
  • No forward assist for a sleek and stylish look


  • Material: 6061-T6 Aluminum
  • Finish: Cerakoted
  • Weight: 8.11 oz.


  • AR-15


  • 1x CMMG Mk4/AR15 Upper Receiver
  • 1x Brass Deflector (installed)
  • 1x CMMG ZEROED Polymer Dust Cover (installed)


CMMG is a major player in the AR parts and accessories market, and they've got the perfect option for those aiming to build a sleek and dependable AR-15—the Mk4/AR15 Upper Receiver.

Minimalist Design, Maximum Performance

Crafted from durable 6061-T6 Aluminum, this upper receiver sports a top-notch Cerakote finish. It is very durable and fully assembled with a lightweight Polymer Dust Cover. Keeping with its minimalist profile, this upper assembly does not have a forward assist, which gives it a sleek and stylish look and decreases its weight.

The CMMG Mk4/AR15 Upper Receiver features a full-length Mil-Spec 1913 Picatinny rail on top for mounting optics, and it has M4 feed ramps for improved reliability.

The Perfect Foundation

The CMMG Mk4/AR15 Upper Receiver is an excellent, well-made AR part with the name recognition and brand standards of CMMG. If you're building a minimalist AR-15, it is an ideal base to start with.

Have a question?

Ask an Expert