5.7x28 Complete Upper 16.1” RESOLUTE™ 100 - CMMG

This is a drop-in caliber conversion for your AR-15, its as easy as fitting this new 5.7 complete upper to your standard lower receiver. CMMG has also included a 40 round magazine for use in your newly configured 5.7x28 AR, making this upper receiver kit fully range-ready as soon as you get your shipment in the mail! Just add some fresh boxes of ammo to the mix and you can start plinking immediately! 

CMMG has designed the upper receiver with a patented radial delayed blowback operating system and includes a full BCG, mil-spec charging handle, A2 compensator, and a 15" M-LOK handguard. These great features and the included 40-round magazine allow for an effortless caliber swap. 

For additional magazines, click HERE!

Technical Specs:

• Barrel: 16.1” 1:9 twist, medium taper 416SS
• Muzzle: A2 comp, threaded 1/2-28
• Material: Forged 7075-T6 AL M4 type upper
• Rail: CMMG RML15 M-Lok handguard
• Receiver Coating: Hard coat anodized receiver and handguard
• Weight: 4lbs 5oz
• Overall Length: 25.2”