6 ARC MOD-2 Complete Upper

The MOD-2 6mm ARC Complete Upper Receiver is engineered for shooters seeking superior ballistic efficiency, flatter trajectories, and enhanced long-range performance from the AR platform. Designed around the high-performance 6mm ARC cartridge, this upper delivers optimized gas system tuning and consistent accuracy across multiple barrel configurations.

Available in 12.5", 14.5", 16", and 18" barrel lengths, each upper is equipped with an exclusive Criterion barrel to ensure match-grade precision and durability. The system is paired with a suppressor-ready muzzle device from HuxWrx, SureFire, or Dead Air, providing compatibility with leading suppressor platforms.

The 14.5" configuration is pinned and welded to meet rifle-length requirements when installed on compatible lowers. All NFA rules apply where applicable.

Upper receivers are offered in Black Type III hard coat anodized.

NOTE: ALL UPPER RECEIVERS MAY HAVE UP TO A 2-3 WEEK LEAD TIME AFTER THE ORDER IS PLACED. All Uppers are Build To Order.

The 14.5" Uppers are pinned and welded for use on rifle lowers. If you do not want your upper pinned and welded please send an email to sales with your order number so we can make a note to not pin your upper.   

While American Defense MFG tries to stay current on all state laws, it is the responsibility of the customer to ensure that the firearm they are purchasing is legal to ship, as presented on our website, to their dealer of choice, and that the dealer is willing to accept the transfer.