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Genesis Arms GEN12 Complete Upper (DPMS GEN1) - 18"

AR-10 Complete Upper Receiver

As low as: $1550.00
Out of stock

This product ships from another warehouse location and not available at our retail store. Orders may take an additional 3-5 business days for processing.

The GEN12 wasn't the 1st "AR Shotgun", but it is the first to use a standard 308 lower.

The GEN12 upper was specifically designed to mate to any DPMS GEN1 308 Lower or other 308 lowers sharing the same pattern.

The GEN12 upper will work with either the shorter DPMS buffer tube or the longer Armalite AR10/308 tubes.

The center of the upper is the short recoil system which cycles the action.  This means there is no gas tube or piston.  The cyclic rate can be tuned by adjusting buffer weights and springs by the end user.

The upper will cycle birdshot or magnums and most everything in between.

It reliably feeds both 2 3/4" shells and 3" shells on a standard short DPMS 308 buffer and spring.  However they recommend a H3 buffer or a Hydraulic buffer when shooting magnums or any 3".

This is sold as an upper so this does not require a FFL to purchase, however, you are responsible to know the laws in your state and purchase accordingly.

Some Assembly required:

Due to the shock and recoil from the 12 guage, and the inherent differences within magazine geometry, you will be provided several parts to replace on your DPMS GEN1 patterned lower to ensure functionality and compatibility.

PROHIBITED SALES to New York, New Jersey, Connecticut, Massachusetts, Maryland, and District of Columbia.  Other Restricted sales include Cook County IL, Gary and E Chicago IN.


  • -7075 Billet Aluminum receiver, hard coat anodized Milspec type III
  • -13” freefloat Handguard with MLOK with top picatinny rail, allows the use of red-dot optics, tactical lights and other accessories
  • -12gauge barrel (18.5”) chambered for 2 ¾” and 3” shells finished in black oxide
  • -BCG and barrel extension Black Oxide finish


*Accessories featured are not included; EOTECH, sights, and vertical grip*

More Information
Product Type AR-10 Complete Upper Receiver
Manufacturer Genesis Arms