AAM4 A4 Stripped Forged Flat Top Upper Receiver

AAM4 A4 Stripped Forged Flat Top Upper Receiver


The AAM4 AR15 Stripped Upper Receiver is one of our most popular products. Forged from 7075-T6 aluminum, this stripped upper is precision CNC machined to mil-spec M16/M4 specifications and featuring M4 feed ramps. Match this upper with one of our AAM4 lower receivers for a high quality solid and dependable fit.

AAM4 AR15 Stripped Upper Receiver


  • Laser Engraved American Paratrooper and AAM4 logos (not shown in photos)
  • Precision CNC Machined from 7075 T6 Aluminum Forging.
  • Hard Coat Anodizing for added strength and durability.
  • M4 Feed Ramps
  • Laser Engraved ÛÏT ۝ Markings
  • M4 Feedramps
  • .250 takedown pin holes
  • Lazer engraved T-marks
  • Machined and assembled right here in Minnesota, USA


  • One AAM4 Stripped Upper Receiver in Anodized Black

History of the “A4” Style upper receiver:

A1 Upper Receiver

The original upper receiver introduced for the platform, the “A1” was developed in the 60’s and installed on the M-16 A1 rifles used by soldiers in the Vietnam War. Ê The “A1” designs distinguishing features included:

  • A Forward Assist
  • A Fixed Carrying Handle
  • A flip up rear sight that adjusted for wind-age (but not elevation)
  • Rear sight is equiped with both short and long range apertures

A2 Upper Receiver

In the early 1980’s the “A2” upper receiver was introduced as an upgrade to the “A1”. Ê The A2 design improvements included:

  • A more advanced rear sight that is adjustable for both elevation as well as windage.

A3 Upper Receiver

The “A3” upper receiver was introduced to allow for a variety of optics to be used without drastically changing the cheek weld used to operate them. Ê The “A3” upper receiver design features the following design improvements:

  • A flat top rail (either picatinny or weaver depending on the model) to allow for a variety of optics and accessories to be mounted.
  • Rifle cuts in the feed ramps.
  • A few “A3” models are available in a “high rise” configuration that extends the base upwards providing a higher scope positioning.

A4 Upper Receiver


The “A4” model upper receiver design (of which the AAM4 A4 forged upper receiver is based) improves upon the “A3” flat top design with the main improvement being:

  • The “A4” model upper receiver employs M4-style feed ramp cuts. Ê These feed ramps improved reliability and opened even more caliber versatility on the platform. Ê The “M4” style feed ramps quickly became the adopted standard accross the industry and they remain the standard to this day.


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